Response
1.1 – Identify the role of receptors in detecting stimuli.
Stimuli are environmental factors that can be either internal or external, these factors trigger a response and the organism reacts accordingly, these reactions can be triggered by things such as light, sound, temperature, pressure, the infliction of pain and/or particular chemicals that may give a response.
A receptor cell is a specialised cell that detects a stimulus, and as a result a nerve impulse may be generated or a hormone produced. There is a wide range of receptor cells that have adapted to specific detection of specific stimuli, these can be found all over the body, such as touch receptors in the skin. In other cases particular receptors are concentrated in an organ, such as the eye, or an endocrine gland such as the adrenal gland. The main Role of these Receptors is to detect an apparent change or threat in the environment that will result in the collaboration of stimuli ultimately leading to a reaction.
http://scienceinspiration.blogspot.com.au/2012/05/touch-and-pain.html
Stimuli are environmental factors that can be either internal or external, these factors trigger a response and the organism reacts accordingly, these reactions can be triggered by things such as light, sound, temperature, pressure, the infliction of pain and/or particular chemicals that may give a response.
A receptor cell is a specialised cell that detects a stimulus, and as a result a nerve impulse may be generated or a hormone produced. There is a wide range of receptor cells that have adapted to specific detection of specific stimuli, these can be found all over the body, such as touch receptors in the skin. In other cases particular receptors are concentrated in an organ, such as the eye, or an endocrine gland such as the adrenal gland. The main Role of these Receptors is to detect an apparent change or threat in the environment that will result in the collaboration of stimuli ultimately leading to a reaction.
http://scienceinspiration.blogspot.com.au/2012/05/touch-and-pain.html
1.2 - Explain that the response to a stimulus involves:
Stimulus - A stimulus is a change in the external or internal environment of an organism, such as heat hair dryer.
Receptor- A receptor is a built in structure in the organisms body that detects this change in the environment, such as skin receptors.
Messenger - A messenger, normally the nerves take the message to the brain, and from there the message is interpreted, and sent to the effector. For example Sensory neurones send messages to the electrochemical messages ending up in the central nervous system, from here the message is sent to the brain and at the same time a reflex arc may connect to the motor neurone, triggering an effector.
Effector- An effector carries out the response, such as the reflex muscle below the patella when this is hit the effector triggers the response.
Response- A response is the ultimate reaction to the stimulus, for example when the hand moves the hair dryer away from the hair when it becomes too close or too hot.
http://resources.mhs.vic.edu.au/science/resources/under_control_summary.htm
http://www.studyblue.com/notes/note/n/the-characteristics-of-living-things/deck/5302681
Stimulus - A stimulus is a change in the external or internal environment of an organism, such as heat hair dryer.
Receptor- A receptor is a built in structure in the organisms body that detects this change in the environment, such as skin receptors.
Messenger - A messenger, normally the nerves take the message to the brain, and from there the message is interpreted, and sent to the effector. For example Sensory neurones send messages to the electrochemical messages ending up in the central nervous system, from here the message is sent to the brain and at the same time a reflex arc may connect to the motor neurone, triggering an effector.
Effector- An effector carries out the response, such as the reflex muscle below the patella when this is hit the effector triggers the response.
Response- A response is the ultimate reaction to the stimulus, for example when the hand moves the hair dryer away from the hair when it becomes too close or too hot.
http://resources.mhs.vic.edu.au/science/resources/under_control_summary.htm
http://www.studyblue.com/notes/note/n/the-characteristics-of-living-things/deck/5302681
1.3 - Identify data sources, gather and process information from secondary sources to identify the range of senses involved in communication.
Refer to table for other examples - Pheromones and the sense of smell are used mostly in animals such as dogs, used for detecting food and in some cases drugs (police dogs).
http://interestingthings.info/wp-content/uploads/2013/04/5-Senses-300x194.jpg
Refer to table for other examples - Pheromones and the sense of smell are used mostly in animals such as dogs, used for detecting food and in some cases drugs (police dogs).
http://interestingthings.info/wp-content/uploads/2013/04/5-Senses-300x194.jpg
2.1 – Describe the anatomy and function of the human eye including the:
Conjunctiva - Continuation of the epidermis of the skin, this protects the cornea at the front of the eyeball against any inflicted friction.
Cornea - Transparent to admit light, the cornea refracts light to help focus the image onto the retina.
Sclera - This is the white of the eye, it consists of a tough coat of fibres, and protects the eyeball against any mechanical damage also maintaining the shape of the eyeball.
Choroid - This is a type of membrane that contains certain pigments and blood vessels, this nourishes the retina, and provides a blood supply to the area, also absorbing light to prevent any internal reflection.
Retina - The retina contains light and photosensitive light-sensitive receptor cells, these are connected to the sensory neurones, leading to a detection of light.
Iris - The iris is the pigmented muscular tissue that surrounds the pupil of the eye this produces the colour of the eye such as blue or green, this can narrow or widen to adjust the amount of light entering the eye.
Lens - The lens of the eye is a flexible transparent structure, which enables light to reach the back of the eye; it also refracts light to allow fine focusing of an image onto the retina.
Aqueous Humor - The Aqueous Humor is a clear watery fluid found inbetween the cornea and the lens, this allows the eye to maintain the shape of the eye and supplies nutrients to the cornea and lens.
Vitreous Humor - This clear jelly-like substance is found behind the lens and in front of the retina, this helps maintain the shape of the back of the eye.
Ciliary Body - The Ciliary body consists of muscles; these muscles support the lens and alter the shape of the lens for accurate vision.
Optic Nerve - The optic nerve consists of bundles of sensory neurons, transmitting impulses that are generated in the retina to the brain.
http://www.biographixmedia.com/human/eye-anatomy.html
Conjunctiva - Continuation of the epidermis of the skin, this protects the cornea at the front of the eyeball against any inflicted friction.
Cornea - Transparent to admit light, the cornea refracts light to help focus the image onto the retina.
Sclera - This is the white of the eye, it consists of a tough coat of fibres, and protects the eyeball against any mechanical damage also maintaining the shape of the eyeball.
Choroid - This is a type of membrane that contains certain pigments and blood vessels, this nourishes the retina, and provides a blood supply to the area, also absorbing light to prevent any internal reflection.
Retina - The retina contains light and photosensitive light-sensitive receptor cells, these are connected to the sensory neurones, leading to a detection of light.
Iris - The iris is the pigmented muscular tissue that surrounds the pupil of the eye this produces the colour of the eye such as blue or green, this can narrow or widen to adjust the amount of light entering the eye.
Lens - The lens of the eye is a flexible transparent structure, which enables light to reach the back of the eye; it also refracts light to allow fine focusing of an image onto the retina.
Aqueous Humor - The Aqueous Humor is a clear watery fluid found inbetween the cornea and the lens, this allows the eye to maintain the shape of the eye and supplies nutrients to the cornea and lens.
Vitreous Humor - This clear jelly-like substance is found behind the lens and in front of the retina, this helps maintain the shape of the back of the eye.
Ciliary Body - The Ciliary body consists of muscles; these muscles support the lens and alter the shape of the lens for accurate vision.
Optic Nerve - The optic nerve consists of bundles of sensory neurons, transmitting impulses that are generated in the retina to the brain.
http://www.biographixmedia.com/human/eye-anatomy.html
2.2 – Identify the limited range of wavelengths of the electromagnetic spectrum detected by humans and compare this range with those of other vertebrates and invertebrates.
The photoreceptor cells in the human eye can detect visible light, which ranges from about 400nm (violet light) to 700nm (red light).
The human eye has evolved to detect colours in bright daylight. We are able to detect colour in the visible range of the spectrum, and we also have sensitive light receptors that mainly detect the 3 regions of the spectrum, these being red, green and blue wavelengths.
The human eye is unable to detect wavelengths such as the violet spectrum or any such UV wave lengths of less than 400nm, that why when we use lemon juice to write a message on paper we can’t see it until we apply the ultra violet light allowing us to see the hidden message, but because we can’t see this violet range of the spectrum we can’t see the ultra violet light being emitted naturally, and therefore cannot see things that this range of light exposes.
Many insects are invertebrates, and are infact able to detect some wavelengths in the UV range of the electromagnetic spectrum; they can do this by using their light sensitive cells, as these cells can detect the shorter wavelengths that humans cannot.
Honey bees are infact unable to see some of the longer wavelengths especially in the red range of the electromagnetic spectrum, and therefore don’t see much red if any at all, and unlike many invertebrates they cannot see more of a colour range than humans, but rather a different range from the UV light range, the blue light range and the green light range, but not the red light range.
Some vertebrates, unlike humans such as birds are able to detect light far into the UV range of the electromagnetic spectrum, and so in addition to this, birds are able to detect light most effectively in the red and green spectrums. And with this said also have the ability to detect light within the blue range of the electromagnetic spectrum.
http://mato48.com/2012/11/11/a-short-guide-for-non-believers/
The photoreceptor cells in the human eye can detect visible light, which ranges from about 400nm (violet light) to 700nm (red light).
The human eye has evolved to detect colours in bright daylight. We are able to detect colour in the visible range of the spectrum, and we also have sensitive light receptors that mainly detect the 3 regions of the spectrum, these being red, green and blue wavelengths.
The human eye is unable to detect wavelengths such as the violet spectrum or any such UV wave lengths of less than 400nm, that why when we use lemon juice to write a message on paper we can’t see it until we apply the ultra violet light allowing us to see the hidden message, but because we can’t see this violet range of the spectrum we can’t see the ultra violet light being emitted naturally, and therefore cannot see things that this range of light exposes.
Many insects are invertebrates, and are infact able to detect some wavelengths in the UV range of the electromagnetic spectrum; they can do this by using their light sensitive cells, as these cells can detect the shorter wavelengths that humans cannot.
Honey bees are infact unable to see some of the longer wavelengths especially in the red range of the electromagnetic spectrum, and therefore don’t see much red if any at all, and unlike many invertebrates they cannot see more of a colour range than humans, but rather a different range from the UV light range, the blue light range and the green light range, but not the red light range.
Some vertebrates, unlike humans such as birds are able to detect light far into the UV range of the electromagnetic spectrum, and so in addition to this, birds are able to detect light most effectively in the red and green spectrums. And with this said also have the ability to detect light within the blue range of the electromagnetic spectrum.
http://mato48.com/2012/11/11/a-short-guide-for-non-believers/
2.3 – Plan, choose equipment or resources and perform a first-hand investigation of a mammalian eye to gather first-hand data to relate structures to functions.
Dissection of bulls eye – Refer to website for detailed method and instructions:
http://www.exploratorium.edu/learning_studio/cow_eye/step01.html
http://nicholaszyh3.weebly.com/uploads/8/6/3/5/8635358/100778449.jpg
Dissection of bulls eye – Refer to website for detailed method and instructions:
http://www.exploratorium.edu/learning_studio/cow_eye/step01.html
http://nicholaszyh3.weebly.com/uploads/8/6/3/5/8635358/100778449.jpg
2.4 – Use available evidence to suggest reasons for the differences in the range of electromagnetic radiation and other animals.
Certain types of snakes, such as rattle snakes, can detect infra-red radiation using a pit organ on their body. This means that they will hunt during the night or move into dark burrows and still be able to see and detect particular endotherms, for example the detection of mice, so this infra-red vision allows them to hunt and detect near by food. They can detect prey by using both their eyes and the pit organ. Humans have very different means of hunting these types of food sources for example if we are looking for a food source in the dark we tend to take torches or some form of light emitting substance with us like a glow stick that allows us to see the visible spectrum that our eyes can detect, therefore allowing us to see as clear as daylight and expose the food we may be hunting for in the dark.
Insects like the honey bee can detect UV radiation, and as many flowers have patterns of UV light rays as they are exposed to them throughout the day, as a source of food for the honey bees this can be detected easily through the use of their UV radiation, directing them to the nectar helping in the pollination progress as well. Human are not able to see these particular wavelengths, but for good reason, as we are not a prime pollinator in natural ecosystems, so it is good that honey bees have it for their purpose of pollination, a food source and survival.
Colour sensitivity – Colour sensitivity is related very closely to the structure of the eye. The number of types of colour sensitive cones and their sensitivity range in many vertebrates determines their colour vision some organisms with compound eyes, such as bees, also have visual cells sensitive to different ranges of the electromagnetic spectrum of radiation.
Snakes and some fish that detect infra-red radiation can easily detect their prey at night, as the heat from their bodies will result in infra-red radiation being emitted, pretty much acting as a target for their prey, allowing these fish and snakes to successfully hunt at night. The fish may detect the prey that would normally be hidden by the background or because of camouflage.
http://www.colours.phy.cam.ac.uk/
Certain types of snakes, such as rattle snakes, can detect infra-red radiation using a pit organ on their body. This means that they will hunt during the night or move into dark burrows and still be able to see and detect particular endotherms, for example the detection of mice, so this infra-red vision allows them to hunt and detect near by food. They can detect prey by using both their eyes and the pit organ. Humans have very different means of hunting these types of food sources for example if we are looking for a food source in the dark we tend to take torches or some form of light emitting substance with us like a glow stick that allows us to see the visible spectrum that our eyes can detect, therefore allowing us to see as clear as daylight and expose the food we may be hunting for in the dark.
Insects like the honey bee can detect UV radiation, and as many flowers have patterns of UV light rays as they are exposed to them throughout the day, as a source of food for the honey bees this can be detected easily through the use of their UV radiation, directing them to the nectar helping in the pollination progress as well. Human are not able to see these particular wavelengths, but for good reason, as we are not a prime pollinator in natural ecosystems, so it is good that honey bees have it for their purpose of pollination, a food source and survival.
Colour sensitivity – Colour sensitivity is related very closely to the structure of the eye. The number of types of colour sensitive cones and their sensitivity range in many vertebrates determines their colour vision some organisms with compound eyes, such as bees, also have visual cells sensitive to different ranges of the electromagnetic spectrum of radiation.
Snakes and some fish that detect infra-red radiation can easily detect their prey at night, as the heat from their bodies will result in infra-red radiation being emitted, pretty much acting as a target for their prey, allowing these fish and snakes to successfully hunt at night. The fish may detect the prey that would normally be hidden by the background or because of camouflage.
http://www.colours.phy.cam.ac.uk/
3.1 – Identify the conditions under which refraction of light occurs.
Light rays travel in straight lines. The refraction of light occurs when light passes from one medium to another medium at an angle other than 90°. Refraction of light refers to the blending of particular light rays. Refraction occurs when light passes through a denser medium such as water, due to the slowing down of speed, which is why when you are cleaning the pool with a leaf collector that the part of the pole that is visible beneath the water looks bent.
http://www.ssc.education.ed.ac.uk/bsl/physics/anglerefractiond.html
http://www.visualphotos.com/image/1x3743411/glass_of_water_and_straw_a_still-life_of_a_glass
Light rays travel in straight lines. The refraction of light occurs when light passes from one medium to another medium at an angle other than 90°. Refraction of light refers to the blending of particular light rays. Refraction occurs when light passes through a denser medium such as water, due to the slowing down of speed, which is why when you are cleaning the pool with a leaf collector that the part of the pole that is visible beneath the water looks bent.
http://www.ssc.education.ed.ac.uk/bsl/physics/anglerefractiond.html
http://www.visualphotos.com/image/1x3743411/glass_of_water_and_straw_a_still-life_of_a_glass
3.2 – Identify the cornea, aqueous humour, lens and Vitreous Humor as refractive media.
In the eye, the refraction of light occurs when light passes from the air to the cornea, from the cornea to the aqueous humor, from the aqueous humor to the lens and from the lens to the vitreous humor, finally focusing the image on a particular point on the retina.
http://www.skinrenewks.com/SkinRenewKs/lasik.aspx
In the eye, the refraction of light occurs when light passes from the air to the cornea, from the cornea to the aqueous humor, from the aqueous humor to the lens and from the lens to the vitreous humor, finally focusing the image on a particular point on the retina.
http://www.skinrenewks.com/SkinRenewKs/lasik.aspx
3.3 – Identify accommodation as the focusing on objects as different distances, describe its achievement through the change in strength of the lens and explain its importance.
Accommodation is the ability of the lens to change shape and focus light from objects at a range of distances. If the lens has a greater curvature it refracts the light to a greater extent and close objects can be put into focus helping us see better. If the lens becomes less curvature it refracts light less and distant objects can be focused. – Accommodation is important be cause it allows the eye to form focused images on the retina from objects at a range of distances from the eye.
Contraction of the ciliary muscles slackens the zonules so they don't pull so much on the lenses. The lenses have a greater curvature, and the eyes can focus on a nearby object. When the ciliary muscles relax, the zonules pull the edges of the lenses so they have less of a curvature, becoming flatter and thinner for distance vision.
Accommodation is important because it allows the eye to form focused images on the retina, from all different distances from the eye. Accommodation of the eye can be achieved mainly through changing the shape and curvature of the lens.
Accommodation is very important as it enables organisms to clearly see distant and close objects; this assists the organism in detecting the basic necessities of life, such as food shelter and even mates etc. enabling the organism to survive.
http://www.sciencelearn.org.nz/Contexts/Light-and-Sight/Sci-Media/Images/Theories-of-eye-accommodation
Accommodation is the ability of the lens to change shape and focus light from objects at a range of distances. If the lens has a greater curvature it refracts the light to a greater extent and close objects can be put into focus helping us see better. If the lens becomes less curvature it refracts light less and distant objects can be focused. – Accommodation is important be cause it allows the eye to form focused images on the retina from objects at a range of distances from the eye.
Contraction of the ciliary muscles slackens the zonules so they don't pull so much on the lenses. The lenses have a greater curvature, and the eyes can focus on a nearby object. When the ciliary muscles relax, the zonules pull the edges of the lenses so they have less of a curvature, becoming flatter and thinner for distance vision.
Accommodation is important because it allows the eye to form focused images on the retina, from all different distances from the eye. Accommodation of the eye can be achieved mainly through changing the shape and curvature of the lens.
Accommodation is very important as it enables organisms to clearly see distant and close objects; this assists the organism in detecting the basic necessities of life, such as food shelter and even mates etc. enabling the organism to survive.
http://www.sciencelearn.org.nz/Contexts/Light-and-Sight/Sci-Media/Images/Theories-of-eye-accommodation
3.4 – Compare the change in the refractive power of the lens from rest to maximum accommodation.
When accommodation occurs the ring of ciliary muscles contract, the tension in the suspensory ligaments (Zonules) is reduced and the lens as a result bulges due to its natural elasticity. The refractive power of the lens increases, therefore shortening the focal length.
To achieve maximum refractive power, or maximum accommodation for the focusing of close objects, the lens must bulge into a rounded shape this allows the eye to focus on close objects. To achieve minimum accommodation, for the focusing of distant objects the lens must relax or become flattened with less of a curvature to enable the focusing of distant objects.http://adithyakiran.wordpress.com/tag/progressive-lenses/
When accommodation occurs the ring of ciliary muscles contract, the tension in the suspensory ligaments (Zonules) is reduced and the lens as a result bulges due to its natural elasticity. The refractive power of the lens increases, therefore shortening the focal length.
To achieve maximum refractive power, or maximum accommodation for the focusing of close objects, the lens must bulge into a rounded shape this allows the eye to focus on close objects. To achieve minimum accommodation, for the focusing of distant objects the lens must relax or become flattened with less of a curvature to enable the focusing of distant objects.http://adithyakiran.wordpress.com/tag/progressive-lenses/
3.5 – Distinguish between myopia and hyperopia and outline how technologies can be used to correct these conditions.
Myopia is short-sightedness. Meaning that a person with Myopia can see objects that are close fairly well, but has no hope of seeing objects that are far away or in the distant as they become out of focus. This is because the rays from distant objects are focused in front of the retina rather than on the retina. The usual cause of myopia is that the eyeball is too elongated or the lens has become too curved. Myopia can be corrected with concave lenses worn for distant viewing, either in the form of glasses or contacts. These lenses cause parallel rays to diverge slightly before they enter the eye so that the lens can focus them on the retina.
Hyperopia on the other hand is long-sightedness. A person with hyperopia, can see objects that are at a distance fairly well, but has a lot of trouble and may not even be able to see things in focus that are close appearing out of focus. The rays from distant objects are focused behind the retina rather than on the retina, and the usual cause for hyperopia is that the eyeball is infact too short. Either too short, shallow or that the lens is flatter, also sometimes with age the lens can become harder reducing its flexibility power or power of accommodation, relaxing so that the only images that are in focus are those that appear at a distance. Hyperopia can be corrected with convex lenses worn for viewing close objects. These lenses cause the parallel light rays to converge slightly before entering the eye, so that the lens can then converge the rays to a particular point on the retina.
In both Myopia and Hyperopia glasses, contact lenses or even some forms of laser eye-surgery can help restore the eye to a condition where the effected person can then focus on both close and distant objects, it is only in extreme cases that these issues cannot be resolved and the person has to accept that they cannot see particular things.
Refractive surgery may also be used to treat both Myopia and Hyperopia. This procedure involved a thin flap of the cornea, being cut and folded back. A laser is then used to reshape the cornea into a more suitable shape, either more rounded (greater curvature) or less rounded (less of a curvature). The fold of skin is then folded back into place. And the patient is to wear a protective patch.http://www.balineye.com/massachusetts/laser-vision-correction-western-massachusetts.htm
Myopia is short-sightedness. Meaning that a person with Myopia can see objects that are close fairly well, but has no hope of seeing objects that are far away or in the distant as they become out of focus. This is because the rays from distant objects are focused in front of the retina rather than on the retina. The usual cause of myopia is that the eyeball is too elongated or the lens has become too curved. Myopia can be corrected with concave lenses worn for distant viewing, either in the form of glasses or contacts. These lenses cause parallel rays to diverge slightly before they enter the eye so that the lens can focus them on the retina.
Hyperopia on the other hand is long-sightedness. A person with hyperopia, can see objects that are at a distance fairly well, but has a lot of trouble and may not even be able to see things in focus that are close appearing out of focus. The rays from distant objects are focused behind the retina rather than on the retina, and the usual cause for hyperopia is that the eyeball is infact too short. Either too short, shallow or that the lens is flatter, also sometimes with age the lens can become harder reducing its flexibility power or power of accommodation, relaxing so that the only images that are in focus are those that appear at a distance. Hyperopia can be corrected with convex lenses worn for viewing close objects. These lenses cause the parallel light rays to converge slightly before entering the eye, so that the lens can then converge the rays to a particular point on the retina.
In both Myopia and Hyperopia glasses, contact lenses or even some forms of laser eye-surgery can help restore the eye to a condition where the effected person can then focus on both close and distant objects, it is only in extreme cases that these issues cannot be resolved and the person has to accept that they cannot see particular things.
Refractive surgery may also be used to treat both Myopia and Hyperopia. This procedure involved a thin flap of the cornea, being cut and folded back. A laser is then used to reshape the cornea into a more suitable shape, either more rounded (greater curvature) or less rounded (less of a curvature). The fold of skin is then folded back into place. And the patient is to wear a protective patch.http://www.balineye.com/massachusetts/laser-vision-correction-western-massachusetts.htm
3.6 – Explain how the production of two different images of a view can result in depth perception.
Some animals have forward facing eyes, meaning that there is a considerable overlap between the views on the left and the right. Because the two eyes are a few centimetres apart, each eye sees a slightly different view of an object. The brain superimposes images so that they appear correctly, because each view is slightly different, as some objects can appear 2D some can appear 3D.
Animals that have the tendency to climb for example monkeys have forward facing eyes, but grazing animals or ground animals such as elephants have eyes on the side of their head so that they have a wider field of view.
Types of vision:
* 3D vision: perceptive distance, depth, height and width of vision.
*Binocular vision: occurs when both eyes are focused on the same visual field. As each eye captures its own image of the view and sends the message to the brain, where the images from each eye overlap, and the brain matches the similarities, notes the differences and the combined picture is that of a 3D stereoscopic picture of the view giving a form of depth perception.
http://www.moillusions.com/2008/12/dont-step-into-danger-3d-chalk-drawings.html
Some animals have forward facing eyes, meaning that there is a considerable overlap between the views on the left and the right. Because the two eyes are a few centimetres apart, each eye sees a slightly different view of an object. The brain superimposes images so that they appear correctly, because each view is slightly different, as some objects can appear 2D some can appear 3D.
Animals that have the tendency to climb for example monkeys have forward facing eyes, but grazing animals or ground animals such as elephants have eyes on the side of their head so that they have a wider field of view.
Types of vision:
* 3D vision: perceptive distance, depth, height and width of vision.
*Binocular vision: occurs when both eyes are focused on the same visual field. As each eye captures its own image of the view and sends the message to the brain, where the images from each eye overlap, and the brain matches the similarities, notes the differences and the combined picture is that of a 3D stereoscopic picture of the view giving a form of depth perception.
http://www.moillusions.com/2008/12/dont-step-into-danger-3d-chalk-drawings.html
3.7 – Plan, choose equipment or resources and perform a first-hand investigation to model the process of accommodation by passing rays of light through convex lenses of different focal lengths.
Practical experiment involving convex and concave lenses, also light-boxes to produce focused light upon these lenses, showing the concentration of rays exposed on the lens of the eye.
http://images.yourdictionary.com/lens
http://www.universetoday.com/82338/concave-lens/
Practical experiment involving convex and concave lenses, also light-boxes to produce focused light upon these lenses, showing the concentration of rays exposed on the lens of the eye.
http://images.yourdictionary.com/lens
http://www.universetoday.com/82338/concave-lens/
3.8 – Analyse information from secondary sources to describe changes in the shape of the eyes lens when focusing on near and far objects.
http://2012books.lardbucket.org/books/introduction-to-psychology/section_08_02.html
http://2012books.lardbucket.org/books/introduction-to-psychology/section_08_02.html
4.1 – Identify photoreceptor cells as those containing light sensitive pigments and explain that these cells convert light images into electrochemical signals that the brain can interpret.
Photoreceptor cells contain light sensitive pigments. The photoreceptor cells then convert light into electrochemical signals that the brain can interpret. An electrochemical signal consists of a wave of sodium and potassium ions which move across the cell membrane of the neurone. Photoreceptor cells take a series of steps in this process:
http://www.google.com.au/search?um=1&safe=strict&hl=en&noj=1&biw=1195&bih=684&complete=0&tbm=isch&sa=1&q=photoreceptor+cells+in+the+eye&oq=photoreceptor+cells+in+the+eye&gs_l=img.3...25852.44986.0.45357.0.0.0.0.0.0.0.0..0.0....0...1c.1.19.img.2cOuQbLtMps
Photoreceptor cells contain light sensitive pigments. The photoreceptor cells then convert light into electrochemical signals that the brain can interpret. An electrochemical signal consists of a wave of sodium and potassium ions which move across the cell membrane of the neurone. Photoreceptor cells take a series of steps in this process:
- The light image strikes the retina and is absorbed by photosensitive pigments in the rods and cones.
- An electrical impulse is generated due to a photochemical change in the rods and cones.
- Bipolar cells in the retina receive the impulse.
- The bipolar cells then stimulate the ganglion cells.
- And finally the axons of the ganglion cells form the optic nerve and transmit messages to the brain.
- The brain can then picture the image and focus it correctly.
http://www.google.com.au/search?um=1&safe=strict&hl=en&noj=1&biw=1195&bih=684&complete=0&tbm=isch&sa=1&q=photoreceptor+cells+in+the+eye&oq=photoreceptor+cells+in+the+eye&gs_l=img.3...25852.44986.0.45357.0.0.0.0.0.0.0.0..0.0....0...1c.1.19.img.2cOuQbLtMps
4.2 – Describe the differences in distribution, structure and function of the photoreceptor cells in the human eye.
The retina consists of a thin sheet of photoreceptor cells. These cells are activated by forms of light energy to produce an impulse; this impulse then travels along the neurons that link to the brain. In the retina there are two types of photoreceptor cells, rods and cones. Both these cells are modified neurons. They are not distributed around the retina uniformity.
Rods are long-rod shaped cells. Which are sensitive to low levels of light but are unable to distinguish between colours. The image formed by the brain obtained from the information from rod cells lack detail. Rods are linked in groups to ingle neurones. Rods are found mainly around the periphery of the retina and there are none at the fovea. Rods are more suited for night vision. Infact it was even proven on Mythbusters that the pirate eye-patch infact did insist them as walking into dark rooms and unveiling an uncovered eye adjusts quicker to darkness due to the rods in the eye. Hen the pupil is dilated more rods will be exposed. Rods also detect movement very well.
The cones of the eye are cells that contain a specific pigment, which is only sensitive to high intensities of light but exist in three different forms, so distinguishing of colours is easier. The number of cones increases towards the centre of the back of the retina. At the centre of the retina is a small area, known as fovea, which has densely packed cones only. The fovea corresponds to the region of maximum visual acuity.
Cones are more suitable for a day vision. In bright light, when the pupil contracts, it will be mainly the cones that are activated. As cones require light of light intensity to stimulate them, it follows that we cannot see colours in poor light. The visual activity is dependent on the number of cone cells per unit area. The more there are the greater the number of impulses which will pass messages on to the brain and the more detailed the image.http://science.howstuffworks.com/life/human-biology/eye2.htm
The retina consists of a thin sheet of photoreceptor cells. These cells are activated by forms of light energy to produce an impulse; this impulse then travels along the neurons that link to the brain. In the retina there are two types of photoreceptor cells, rods and cones. Both these cells are modified neurons. They are not distributed around the retina uniformity.
Rods are long-rod shaped cells. Which are sensitive to low levels of light but are unable to distinguish between colours. The image formed by the brain obtained from the information from rod cells lack detail. Rods are linked in groups to ingle neurones. Rods are found mainly around the periphery of the retina and there are none at the fovea. Rods are more suited for night vision. Infact it was even proven on Mythbusters that the pirate eye-patch infact did insist them as walking into dark rooms and unveiling an uncovered eye adjusts quicker to darkness due to the rods in the eye. Hen the pupil is dilated more rods will be exposed. Rods also detect movement very well.
The cones of the eye are cells that contain a specific pigment, which is only sensitive to high intensities of light but exist in three different forms, so distinguishing of colours is easier. The number of cones increases towards the centre of the back of the retina. At the centre of the retina is a small area, known as fovea, which has densely packed cones only. The fovea corresponds to the region of maximum visual acuity.
Cones are more suitable for a day vision. In bright light, when the pupil contracts, it will be mainly the cones that are activated. As cones require light of light intensity to stimulate them, it follows that we cannot see colours in poor light. The visual activity is dependent on the number of cone cells per unit area. The more there are the greater the number of impulses which will pass messages on to the brain and the more detailed the image.http://science.howstuffworks.com/life/human-biology/eye2.htm
4.3 – Outline the role of rhodopsin in rods.
Rhodopsin’s or light sensitive pigments. When light enters a rod cell, it splits rhodopsin molecule into its two components. This reaction results in an impulse in the neurone attached to the rod or cone. The two products slowly recombine, ready to be split again by more light. This is known as the visual cycle. Rods contain rhodopsin that is sensitive to blue-green light. Rhodopsin’s consist of opsin and retinal. The rhodopsin’s in rods are sensitive to light and when they absorb light it changes shape and begins a series of chemical reactions. These reactions produce a generator potential that starts a nervous impulse. Following this sequence, more rhodopsin can be re-synthesised using ATP. The Rods are especially used for night vision.http://justinpamute.wordpress.com/
Rhodopsin’s or light sensitive pigments. When light enters a rod cell, it splits rhodopsin molecule into its two components. This reaction results in an impulse in the neurone attached to the rod or cone. The two products slowly recombine, ready to be split again by more light. This is known as the visual cycle. Rods contain rhodopsin that is sensitive to blue-green light. Rhodopsin’s consist of opsin and retinal. The rhodopsin’s in rods are sensitive to light and when they absorb light it changes shape and begins a series of chemical reactions. These reactions produce a generator potential that starts a nervous impulse. Following this sequence, more rhodopsin can be re-synthesised using ATP. The Rods are especially used for night vision.http://justinpamute.wordpress.com/
4.4 – Identify that there are three types of cones, each containing a separate pigment sensitive to either blue, red or green light.
There are three different types of cones, these cones contain different photopigments. The trichromatic theory of colour vision suggests that each is sensitive to a different range of wavelengths, as seen above. These correspond to the colours red, blue and green.
The sensitivity of these photopigments is broad enough to allow them to cover the full spectrum of visible light. Each pigment is thought to be located on different cones, and different colours are perceived from the brain, from the sensory input from combinations of the three cone types. Therefore the brain builds up a generated colour picture according to the number of impulses received from the three types of cones.
There are three types of cones in the human eye, each is sensitive to a different colour, either of red, green or blue and its corresponding region of the colour spectrum.
Long wavelength cones detect red, middle wavelength cones detect green, and short wavelength cones detect blue.
Each type of cone contains a different light sensitive pigment.
http://www.cbu.edu/~seisen/Photosynthesis.htm
There are three different types of cones, these cones contain different photopigments. The trichromatic theory of colour vision suggests that each is sensitive to a different range of wavelengths, as seen above. These correspond to the colours red, blue and green.
The sensitivity of these photopigments is broad enough to allow them to cover the full spectrum of visible light. Each pigment is thought to be located on different cones, and different colours are perceived from the brain, from the sensory input from combinations of the three cone types. Therefore the brain builds up a generated colour picture according to the number of impulses received from the three types of cones.
There are three types of cones in the human eye, each is sensitive to a different colour, either of red, green or blue and its corresponding region of the colour spectrum.
Long wavelength cones detect red, middle wavelength cones detect green, and short wavelength cones detect blue.
Each type of cone contains a different light sensitive pigment.
- Erythrolabe = Red
- Chlorolabe = Green
- Cyanolabe = Blue
http://www.cbu.edu/~seisen/Photosynthesis.htm
4.5 – Explain that colour blindness in humans results from the lack of one or more pigments in the cones.
As cones are used to detect colour, and the detection of colour comes from the photopigments in the cones, the lack of one or more of these photopigments may result in colour blindness. Normally colour-blindness occurs when there is a lack of one or more of these colour photopigments within the cones, and normally colours that are confused the most due to colour blindness are, brown, green and red.
Colour blindness also means that the person is unable to see certain colours and has some form of colour vision deficiency. There are a range of colour blindness conditions ranging from only a slight difficulty distinguishing different shades of the same colour to the rare inability to distinguish any colours.
Sometimes colour blindness can occur in a variety of ways, for instance sometimes one or more types of cones don’t function correctly, or they may be absent altogether. The incorrect functioning could be an inability to manufacture the required visual pigment or the pigment is defective. The most common type of colour-blindness is that of red-green, in which the cones are not receptive to red and green lights due to the absent or missing cones.http://understandinggraphics.com/design/designing-for-color-blindness/
As cones are used to detect colour, and the detection of colour comes from the photopigments in the cones, the lack of one or more of these photopigments may result in colour blindness. Normally colour-blindness occurs when there is a lack of one or more of these colour photopigments within the cones, and normally colours that are confused the most due to colour blindness are, brown, green and red.
Colour blindness also means that the person is unable to see certain colours and has some form of colour vision deficiency. There are a range of colour blindness conditions ranging from only a slight difficulty distinguishing different shades of the same colour to the rare inability to distinguish any colours.
Sometimes colour blindness can occur in a variety of ways, for instance sometimes one or more types of cones don’t function correctly, or they may be absent altogether. The incorrect functioning could be an inability to manufacture the required visual pigment or the pigment is defective. The most common type of colour-blindness is that of red-green, in which the cones are not receptive to red and green lights due to the absent or missing cones.http://understandinggraphics.com/design/designing-for-color-blindness/
4.6 – Process and analyse information from secondary sources to compare and describe the nature and functioning of photoreceptor cells in mammals, insects and in one other animal.
http://www.google.com.au/url?sa=i&rct=j&q=drawing+of+an+eye&source=images&cd=&docid=qFsSx3LiU2KaHM&tbnid=2XhUKTSL0CVo_M:&ved=&url=http%3A%2F%2Fkatepowellart.deviantart.com%2Fart%2FEye-drawing-294039860&ei=XlvjUcnnGYr5kAXf0oC4BA&bvm=bv.48705608,d.dGI&psig=AFQjCNGIdaFbtHVlqpkXC2L_d-7T0ZPG1A&ust=1373940958767947
http://www.google.com.au/search?um=1&safe=strict&hl=en&noj=1&biw=1195&bih=684&complete=0&tbm=isch&sa=1&q=bees+eye+diagram&oq=bees+eye+diagram&gs_l=img.3...138413.143047.0.143318.0.0.0.0.0.0.0.0..0.0....0...1c.1.19.img.0lB-sh4FVB0#facrc=_&imgdii=_&imgrc=GXGisvy5Q4EF-M%3A%3BrECsUJqpK5uwIM%3Bhttp%253A%252F%252Fwww.bbka.org.uk%252Flocal%252Fslough-windsor-maidenhead%252Fbm~pix%252Fpicture-120~s600x600.png%3Bhttp%253A%252F%252Fwww.bbka.org.uk%252Flocal%252Fslough-windsor-maidenhead%252Farticles%252Fa-birds-eye-view-of-the-world~print.shtml%3B275%3B163
http://www.google.com.au/url?sa=i&rct=j&q=drawing+of+an+eye&source=images&cd=&docid=qFsSx3LiU2KaHM&tbnid=2XhUKTSL0CVo_M:&ved=&url=http%3A%2F%2Fkatepowellart.deviantart.com%2Fart%2FEye-drawing-294039860&ei=XlvjUcnnGYr5kAXf0oC4BA&bvm=bv.48705608,d.dGI&psig=AFQjCNGIdaFbtHVlqpkXC2L_d-7T0ZPG1A&ust=1373940958767947
http://www.google.com.au/search?um=1&safe=strict&hl=en&noj=1&biw=1195&bih=684&complete=0&tbm=isch&sa=1&q=bees+eye+diagram&oq=bees+eye+diagram&gs_l=img.3...138413.143047.0.143318.0.0.0.0.0.0.0.0..0.0....0...1c.1.19.img.0lB-sh4FVB0#facrc=_&imgdii=_&imgrc=GXGisvy5Q4EF-M%3A%3BrECsUJqpK5uwIM%3Bhttp%253A%252F%252Fwww.bbka.org.uk%252Flocal%252Fslough-windsor-maidenhead%252Fbm~pix%252Fpicture-120~s600x600.png%3Bhttp%253A%252F%252Fwww.bbka.org.uk%252Flocal%252Fslough-windsor-maidenhead%252Farticles%252Fa-birds-eye-view-of-the-world~print.shtml%3B275%3B163
4.7 – Process and analyse information from secondary sources to describe and analyse the use of colour for communication in animals and relate this to the occurrence of colour vision in animals.
Birds are strongly attracted to the colour red and therefore frequently visit red flowers, their photoreceptor pigments are adapted to absorb wavelengths of light in the red region of the electromagnetic spectrum, and so objects that are of the colour red, appear more visible to them.Primates, such as monkeys eat fruit, for example bananas. Their colour vision enables them to detect the colours of fruit and to determine when the fruit is ripe and ready to eat.
The use of colour for communication is only effective, if the animals are receiving the message from means of having colour vision, for example humming birds, but other types of animals use other senses more than their colour to depend on food sources such as dogs, as they depend more on their sense of smell and hearing for communication.http://www.birdsasart.com/bn278.htm
http://www.mhpbooks.com/tag/curious-george/
Birds are strongly attracted to the colour red and therefore frequently visit red flowers, their photoreceptor pigments are adapted to absorb wavelengths of light in the red region of the electromagnetic spectrum, and so objects that are of the colour red, appear more visible to them.Primates, such as monkeys eat fruit, for example bananas. Their colour vision enables them to detect the colours of fruit and to determine when the fruit is ripe and ready to eat.
The use of colour for communication is only effective, if the animals are receiving the message from means of having colour vision, for example humming birds, but other types of animals use other senses more than their colour to depend on food sources such as dogs, as they depend more on their sense of smell and hearing for communication.http://www.birdsasart.com/bn278.htm
http://www.mhpbooks.com/tag/curious-george/
5.1 – Explain why sound is a useful and versatile form of communication.
Sound is a form of energy that travels in waves (Compression waves). Sound waves each have a different frequency and sound must pass through a particular medium, either solid, liquid or gas through which sound waves must travel in order for sound to be made. Sound cannot travel through a vacuum, that is why there is no sound in space.
Sound is a common form of communication throughout a vast variety of species, this is because in the space of sound there are so many various sounds to be made. And in that sound has become very useful, in both day and night. Sound can travel over long distances and can bend around corners, and bounce off walls. Sound is very versatile as it can be heard as the actual sound or a variation of the sound such as when someone talks through a microphone, sound can be projected by raising of frequencies and the force it is emitted at, sound can also be amplified. An individual can produce a variety of sounds.
Some benefits of sound:
Sound is a form of energy that travels in waves (Compression waves). Sound waves each have a different frequency and sound must pass through a particular medium, either solid, liquid or gas through which sound waves must travel in order for sound to be made. Sound cannot travel through a vacuum, that is why there is no sound in space.
Sound is a common form of communication throughout a vast variety of species, this is because in the space of sound there are so many various sounds to be made. And in that sound has become very useful, in both day and night. Sound can travel over long distances and can bend around corners, and bounce off walls. Sound is very versatile as it can be heard as the actual sound or a variation of the sound such as when someone talks through a microphone, sound can be projected by raising of frequencies and the force it is emitted at, sound can also be amplified. An individual can produce a variety of sounds.
Some benefits of sound:
- Sound can be used to communicate messages from one person to another.
- Sound can travel through all sorts of substances such as water and solid objects mainly air.
- You can yell something out or make a sound and it can be heard without seeing the actual source or person that is making the sound. Such methods are used with sound being heard through the radio, as a lot of the time we can’t see the singer or radio presenter who is talking through the radio so this is another benefit.
5.2 – Explain that sound is produced by vibrating objects and that the frequency of the sound is the same as the frequency of the vibration of that source of sound.
Sound is infact a form of energy that requires a medium. It cannot travel in a vacuum. Sound is a longitudinal wave where the particles move backwards and forwards in the direction of the wave. Sound is a form of energy produced by a series of vibrations. The vibrations causes nearby air particles to vibrate back and forth, and these particles cause other particles to vibrate at the same frequency, causing a particular sound at that frequency.
Sound is infact a form of energy that requires a medium. It cannot travel in a vacuum. Sound is a longitudinal wave where the particles move backwards and forwards in the direction of the wave. Sound is a form of energy produced by a series of vibrations. The vibrations causes nearby air particles to vibrate back and forth, and these particles cause other particles to vibrate at the same frequency, causing a particular sound at that frequency.
5.3 – Outline the structure of the human larynx and the associated structures that assist the production of sound.
The larynx is responsible for the production of sound, directly located below the tongue and soft palate. Located within the larynx are the vocal cords, these are muscles, that can alter pitch by altering their tension and various positions, together the larynx the toungue the hard and soft palate produce sound.
The larynx also known as voice box, is found directly under the tongue and soft palate. Inside the larynx are the vocal-cords, these are muscles, which can be adjusted to produce different sounds, and pitches by altering the positioning and tension applied.
http://justinpamute.wordpress.com/
The larynx is responsible for the production of sound, directly located below the tongue and soft palate. Located within the larynx are the vocal cords, these are muscles, that can alter pitch by altering their tension and various positions, together the larynx the toungue the hard and soft palate produce sound.
The larynx also known as voice box, is found directly under the tongue and soft palate. Inside the larynx are the vocal-cords, these are muscles, which can be adjusted to produce different sounds, and pitches by altering the positioning and tension applied.
http://justinpamute.wordpress.com/
5.4 – Plan and perform a first-hand investigation to gather data to identify the relationship between wave-length frequency and pitch of a sound.
Together the tongue along with the larynx and the hard and soft palates, make speech possible, the vocal cord produce vibrations and ultimately sound which can be altered to make different noises normally by the tongue teeth or lips, producing various pitches of sound, that’s why people try and perfect their technique whilst singing in order to manipulate the noises produced.
http://sub.allaboutcircuits.com/images/quiz/01821x02.png
Together the tongue along with the larynx and the hard and soft palates, make speech possible, the vocal cord produce vibrations and ultimately sound which can be altered to make different noises normally by the tongue teeth or lips, producing various pitches of sound, that’s why people try and perfect their technique whilst singing in order to manipulate the noises produced.
- Wavelength is the distance occupied by one complete wave measured in meters per second
- Amplitude is the maximum distance a point moves from its rest position when a wave passes also measures in meters per second.
- Frequency is the number of waves that pass a point in one second with the unit of hertz. 1 unit per second.
http://sub.allaboutcircuits.com/images/quiz/01821x02.png
5.5 – Gather and process information from secondary sources to outline and compare some of the structures used by animals to produce sound.
All sorts of animals use all sorts of sounds for things such as communication, mating calls and other forms of communication and interaction.
http://www.posterstoreuk.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/B/u/Bugs-life-a-bug-27s-life-46534_1024_768_2.jpghttp://intrd187-f11-grosovsky.wikispaces.umb.edu/file/view/echolocation.jpg/252058376/385x209/echolocation.jpg
http://www2.hawaii.edu/~zinner/101/students/YvetteEcholocation/echolocation.jpg
All sorts of animals use all sorts of sounds for things such as communication, mating calls and other forms of communication and interaction.
- Crickets and other bugs: Crickets and other bugs use friction of the back legs or rub together the veins on their wings, this form of movement produces sounds, these sounds are then used to communicate with other crickets and predators either to warn them off or draw them in, using their calls.
http://www.posterstoreuk.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/B/u/Bugs-life-a-bug-27s-life-46534_1024_768_2.jpghttp://intrd187-f11-grosovsky.wikispaces.umb.edu/file/view/echolocation.jpg/252058376/385x209/echolocation.jpg
http://www2.hawaii.edu/~zinner/101/students/YvetteEcholocation/echolocation.jpg
6.1 – Outline and compare the detection of vibrations by insects, fish and mammals.
Insects: Insects have hearing organs in lots of parts of their bodies, they have though three main sound detection organs. These include:
http://www.stanprokopenko.com/blog/images/drawears/finished-ear.jpg
Insects: Insects have hearing organs in lots of parts of their bodies, they have though three main sound detection organs. These include:
- Tympanic organs – These consist of a network of membranes stretched across an air capsule. On a grasshoppers legs or crickets legs this is where you can locate the tympanic organs. When sound waves reach this area the membrane vibrates and as a result stimulates the hair cells, and an electro-chemical message is sent via the nerves to the brain.
- Auditory hairs – Many insects have these, they tend to cover the majority of the insect and are very sensitive to sound waves. Each of these hairs have different lengths and stiffness, and respond to vibrations at a range of different frequencies. These hairs are normally present on the antennae and the legs.
- Vibration receptors – Some insects that fly at night have certain types of adaptations to adapt to sound without the assistance of vision, normally this occurs in mammals such as bats but can occur in insects and/or be detected by insects. The main vibration receptors are special receptors that are specifically designed to detect ultrasonic waves, or ultrasonic sounds produced by bats. For instance there is a certain moth called the hawk moth that uses two of its modified mouth parts to hear the ultrasonic calls of bats, and since bats sometimes eat moths, they can avoid becoming prey, and has therefore become a physiological survival mechanism.
- Internal ears – Fish unlike many organisms don’t have ears that are visible, but they do infact have special detection organs built into their anatomy. The inner ear of a fish consists of the otolith and the labyrinth, it is the movement of the sensory hair cells within the otolith that allow the fish to detect and interpret sounds.
- Lateral line – This is a visible line along the body of fish. It consists of fluid-filled canals that are collections of sensory hairs known as neuromasts. The neuromasts respond to low levels sound frequency. The neuromasts consist of small hair cells that are able to detect vibrations in the surrounding environment water.
- Swim bladder – The swim bladder is very important for the equalising of pressure between the water and the buoyancy. It also acts as an amplifier to any sound, passing the vibrations directly to the ear allowing the fish to hear any changes around them that may interfere.
http://www.stanprokopenko.com/blog/images/drawears/finished-ear.jpg
6.2 – Describe the anatomy and function of the human ear, including:
http://health-advisors.org/human-ear-diagram/
http://health-advisors.org/human-ear-diagram/
6.3 – Outline the role of the Eustachian tube.
This tube is very narrow it runs from the middle ear all the way to the pharynx (back throat). Its role is to equalise pressure between the inner and outer ear. This assists the tympanic membrane as it allows it to vibrate properly and not have to accommodate itself for other roles. This tube opens when the body, yawns, swallows and sneezes. This tube helps the middle ear equalise any present pressure.
http://www.merckmanuals.com/media/home/figures/ENT_eustachian_tube.gif
This tube is very narrow it runs from the middle ear all the way to the pharynx (back throat). Its role is to equalise pressure between the inner and outer ear. This assists the tympanic membrane as it allows it to vibrate properly and not have to accommodate itself for other roles. This tube opens when the body, yawns, swallows and sneezes. This tube helps the middle ear equalise any present pressure.
http://www.merckmanuals.com/media/home/figures/ENT_eustachian_tube.gif
6.4 – Outline the path of a sound wave through the external, middle and inner ear, and identify the energy transformations occur.
Sound waves enter the pinna and travel along the auditory canal, causing the tympanic membrane (ear drum) to vibrate. These vibrations are amplified by the ossicles in the middle ear. These tiny bones join the inner ear to the oval window. The cochlea is a spiral- shaped, fluid filled structure within the inner ear. Located within is the organ of corti. Within the organ of Corti there are tiny hair cells that are located on the basilar membrane. These are in contact with the tectorial membrane. When vibrations reach the hair cell the message is converted into an electrochemical response witch travels through the auditory nerve to the brain.https://s3.amazonaws.com/engrade-myfiles/4019665392495042/Pathway_of_sound_detection.jpg
Sound waves enter the pinna and travel along the auditory canal, causing the tympanic membrane (ear drum) to vibrate. These vibrations are amplified by the ossicles in the middle ear. These tiny bones join the inner ear to the oval window. The cochlea is a spiral- shaped, fluid filled structure within the inner ear. Located within is the organ of corti. Within the organ of Corti there are tiny hair cells that are located on the basilar membrane. These are in contact with the tectorial membrane. When vibrations reach the hair cell the message is converted into an electrochemical response witch travels through the auditory nerve to the brain.https://s3.amazonaws.com/engrade-myfiles/4019665392495042/Pathway_of_sound_detection.jpg
6.5 – Describe the relationship between the distribution of hair cells in the organ of corti and the detection of sounds of different frequencies.
Sound frequency is dectected in the organ of corti. The organ of corti has three main components
Sound frequency is dectected in the organ of corti. The organ of corti has three main components
- The basilar Membrane: The Basilar Membrane is composed of transverse fibres of varying lengths. Vibrations received at the oval window are transmitted through the fluids of the cochlea causing the fibres to vibrate at different places according to frequency.
- The Hair Cells: The basilar membrane vibrates and the hair cells are then pushed against the tectorial membrane. This causes the hair cells to send an electrochemical impulse along the auditory nerve to the brain.
- The Tectorial Membrane: is the source of transmission of the electrochemical impulses sent to the brain.
6.6 – Outline the role of the sound shadow cast by the head in the location of sound.
Different organisms have different ways of locating sound or the source of sound, the difference in time between the sound arriving at each ear, and the difference in the intensity of the sound. This is due to the sound shadow casted by the head this means that one ear will receive a less intensive sound than the other ear. Because each ear is situated on opposite sides of the head humans in order to detect the source of sound tend to move their heads to the possible direction that the sound is coming from, this allows the intensity of sound to become equal pin-pointing the location of the source of sound. Other organisms have mobile ears, this helps them identify the source of sound.http://dtrangyr12bio.wikispaces.com/file/view/001.jpg/151331181/369x291/001.jpg
Different organisms have different ways of locating sound or the source of sound, the difference in time between the sound arriving at each ear, and the difference in the intensity of the sound. This is due to the sound shadow casted by the head this means that one ear will receive a less intensive sound than the other ear. Because each ear is situated on opposite sides of the head humans in order to detect the source of sound tend to move their heads to the possible direction that the sound is coming from, this allows the intensity of sound to become equal pin-pointing the location of the source of sound. Other organisms have mobile ears, this helps them identify the source of sound.http://dtrangyr12bio.wikispaces.com/file/view/001.jpg/151331181/369x291/001.jpg
7.1 – Identify that a nerve is a bundle of neuronal fibres. The nerve cells are the base units for the nervous system, neurones are specialised for transmitting signals from one part of the body to another. These nerves are made up of bundles known as neuronal fibres sometimes called axons.http://www.medtrng.com/anatomy%20lesson/Image230.gif
7.2 – identify neurones as nerve cells that are the transmitters of signals by electro-chemical changes in their neuron is a nerve cells that transmits an impulse from one place in the body to another.
A neuron is a nerve cells that transmits an impulse from one place in the body to another.
Nerve impulses travel along neurons by electrical and chemical changes. An electrical impulse then travels from the dendrites of a neuron to the axon. From here a neurotransmitter diffuse across the synapse to the membrane of the dendrites of the next neuron. This initiates a form of electrical signal in the next neuron and the process is repeated along the nerve.
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html
http://outreach.mcb.harvard.edu/animations/actionpotential_short.swf
7.3 – Define the term threshold and explain why not all stimuli generate an action potential.
Threshold – The amount of positive charge in membrane potential which is required to produce an action potential. Each stimulus either produces a full action potential or not at all. Signals are then transmitted from one neuron to the next. An impulse or signal is then transmitted by electrochemical changes in the neurons membrane.
http://www.uic.edu/classes/bios/bios100/lectures/action_potential.jpg
Threshold – The amount of positive charge in membrane potential which is required to produce an action potential. Each stimulus either produces a full action potential or not at all. Signals are then transmitted from one neuron to the next. An impulse or signal is then transmitted by electrochemical changes in the neurons membrane.
http://www.uic.edu/classes/bios/bios100/lectures/action_potential.jpg
7.4 – Identify those areas of the cerebrum involved in the perception and interpretation of light and sound.
The cerebrum is responsible for all conscious activity. This means that different regions of the cerebrum control the vision and colour recognition, via the optical nerves. Sound is then processed in two different areas known as the Broca’s area and the Wernicke’s area.
The broca’s area is mainly involved in the production of speech. It is then from here that this information is transmitted to Wernicke’s area this is where words are then interpreted.
http://www.liquidarea.com/wp-content/uploads/2009/10/broca_area.jpg
The cerebrum is responsible for all conscious activity. This means that different regions of the cerebrum control the vision and colour recognition, via the optical nerves. Sound is then processed in two different areas known as the Broca’s area and the Wernicke’s area.
The broca’s area is mainly involved in the production of speech. It is then from here that this information is transmitted to Wernicke’s area this is where words are then interpreted.
http://www.liquidarea.com/wp-content/uploads/2009/10/broca_area.jpg
7.5 – Explain, using specific examples, the importance of correct interpretation of signals by the brain for the coordination of animal behaviour.
Due to environmental change on a regular basis, sensory organs such as the eyes and ears are able to detect these changes and through electrochemical processes can pass on this information to the brain, the brain then interprets this information and will send an impulse to the effector organs for example muscles. It is essential that these signals are interpreted correctly by the brain otherwise movements would be randomly occurring. This particular random movement can be the result of a form of brain damage or cell damage within the brain, this results in the incorrect signals being sent to organs and thus can affect a persons life dramatically. For example, damage to the temporal lobe (part of brain), may result in the inability to understand certain words and construct sentences, this can lead to further developmental problems, resulting in the difficult coordination of movement.
Due to environmental change on a regular basis, sensory organs such as the eyes and ears are able to detect these changes and through electrochemical processes can pass on this information to the brain, the brain then interprets this information and will send an impulse to the effector organs for example muscles. It is essential that these signals are interpreted correctly by the brain otherwise movements would be randomly occurring. This particular random movement can be the result of a form of brain damage or cell damage within the brain, this results in the incorrect signals being sent to organs and thus can affect a persons life dramatically. For example, damage to the temporal lobe (part of brain), may result in the inability to understand certain words and construct sentences, this can lead to further developmental problems, resulting in the difficult coordination of movement.
7.6 – perform a first-hand investigation using stained prepared slides and/or electron micrographs to gather information about neurons and nerves.
http://www.empathiceducation.com/media/neuron.jpg
http://s3.hubimg.com/u/5095586_f520.jpg
http://www.empathiceducation.com/media/neuron.jpg
http://s3.hubimg.com/u/5095586_f520.jpg
7.7 –Perform a first-hand investigation to examine an appropriate mammalian brain or model of a human brain to gather information to distinguish the cerebrum, cerebellum and medulla oblongata and locate the regions involved in speech, sigh and sound perception.
http://www.biologyjunction.com/images/sheep-brain-sagittal.jpg
http://www.biologyjunction.com/images/sheep-brain-sagittal.jpg
7.8 – present information from secondary sources to graphically represent a typical action potential.
http://www.intechopen.com/source/html/37969/media/image2_w.jpg
http://outreach.mcb.harvard.edu/animations/actionpotential_short.swf
http://www.intechopen.com/source/html/37969/media/image2_w.jpg
http://outreach.mcb.harvard.edu/animations/actionpotential_short.swf