VCE Biology Question Thread

[sparkyblossom]

can someone give me one of two examples of the stimulus response model (nervous system)
thanks!!

The classic 'touched-a-hot-stove' example 
Heat receptors in the skin of your hand detect the heat.
The message is converted into an electrical signal that travels along your nerve pathway.
It reaches your spinal cord which sends back a message to the muscles in your hand.
Muscles respond by contracting so your hand pulls away from the stove.

Hope this helped!

[theBRENDAN97]

Do we need to know about cell connections: occluding, anchoring, plasmodesmata,etc?
Thanks.

[melons]

Do we need to know about cell connections: occluding, anchoring, plasmodesmata,etc?
Thanks.

I don't think we will need to know it in too much detail. I believe that the most that will be asked may be a multiple choice question. I haven't come across any in my revision so far.

[vox nihili]

Do we need to know about cell connections: occluding, anchoring, plasmodesmata,etc?
Thanks.

Hell no.

[shivaji]

can someone explain what short day and long day plants are and how they operate?

[Jason12]

how can a tissue with specific receptors to a hormone, eventually lose it's response to the hormone?

[anat0my]

What is microarray technology and what is it used for? Thanks.

[vox nihili]

how can a tissue with specific receptors to a hormone, eventually lose it's response to the hormone?

Outside of course: if you keep activating certain receptors, they get endocytosed and digested by the cell.

[anat0my]

how can a tissue with specific receptors to a hormone, eventually lose it's response to the hormone?

Just adding on to what Mr.T-Rav said; An interesting example of this is when you're unable to smell certain scents such as your house smell or an overused perfume because you're olfactory system doesn't register it anymore. I think that overtime the receptor is degraded for it. Not entirely sure about this but thought it was an interesting concept.

[vox nihili]

Just adding on to what Mr.T-Rav said; An interesting example of this is when you're unable to smell certain scents such as your house smell or an overused perfume because you're olfactory system doesn't register it anymore. I think that overtime the receptor is degraded for it. Not entirely sure about this but thought it was an interesting concept.

It's got to do with the number of action potentials the receptor fires. So when it first gets the smell, it'll fire like crazy, but over time it gets "tired" and fires more and more slowly. Not exactly sure of the exact details of this, but I'm sure anyone interested could find out by googling tonic receptor.

[millie96]

Do we have to know about feedback responses (e.g. negative feedback), or information including thyroxin and thyroid systems?

Also to what degree do we need to know about nerves and nerve impulses?

[RazzMeTazz]

Would it be correct to say that enzymes can not be used indefinitely because:
1.) They are subject to denaturation when exposed to conditions outside of their optimal range.
2.) They deteriorate over time.

Is the second reason correct?

[RazzMeTazz]

What would be the pro of enzymes being able to work in either directions (since metabolic reactions are reversible) ?

[grannysmith]

Are hormones always produced and secreted by endocrine cells into extracellular fluid?

Edit: Also, when describing the process of transmitting an action potential to subsequet neurons, is it necessary to mention the involvement of calcium ions? If so, would it suffice to say that "calcium ions move towards the synaptic knob"?

[shivaji]

do we still have to know the differences between the individual plant hormones for the current study design?