last minute help (1 Viewer)

[~*pixie_poo*~]

i am having difficulty with the question in the 2002 (i think) HSC, which was 8 marks and was:


"the light singnal reaching the retina is transformed into electrochemical signals.

Describe the different structures and processes in the retina that can acheive the energy transformation described above"

Is this where we have to talk about the different layers of the retina?? i dont have an answer to this question.. would anyone be able to help?? sorry for the short notice people..

 

[Bokky]

ok basically what you have to do is describe the energy transformations occuring from when the light hits the retina to the point when the electrochemical signals are sent to the brain and the structures/features which make this possible.

So...the light is absorbed by the photoreceptor cells (rhodopsins and photopsins). The rhodopsin changes shape and sends the information to the bipolar cells and horizontal cells via branches. These bipolar cells then send the info to the ganglion cells and amacrine cells also through the branches. This are transformed into nerve impulses (electrical signals). This is then sent to the brain which gives us the sensation of vision.

I looked off a diagram from a sheet my teacher gave me so My answer mite be wrong but yeah, hope that helped anyways. good luck

 

[Twiggyy]

the light singnal reaching the retina is transformed into electrochemical signals.

Describe the different structures and processes in the retina that can acheive the energy transformation described above"

when they say structures and processes ill probably focus more on rods and cones as they are specific structures in the retina and how they achieve energy transformation like rods are highly sensetive to light usually used at night and cones are used for visual acuity bla bla.. and their different shapes and numbers because when they say light signal.. theyre not very specific if it is a certain colour or something else so u can pretty much discuss heaps of things and since its 8 marks u can put in i guess how rodopsin is formed and the visual cycle, and the role of nerves involved. im hopin thats correct?

 

[~*pixie_poo*~]

oh well!! it wasnt even in the test. thanks anyway...