VCE Biology Question Thread

[cosine]

Isn't it cloning using the nucleus from an embryonic cell (stem cell)?
So you have a nucleus donor - you remove the nucleus out of an embryonic cell of a particular animal (Animal A) and you take an enucleated (no nucleus) egg cell from another animal (Animal B) and put Animal A's nucleus into Animal B's egg cell.
The resulting individual will have the exact genetic makeup as the nucleus donor (in this case, Animal A).

 

Thank you. Got a few qs:

1. Do we need to know about the types of stem cells? (totipotent, pluripotent, multipotent?) Or what about embryonic stem cells and somatic stem cells?

2. How much do we need to know about embryo splitting? Is it just that the embryo cells are split into two, using a think glass needle in the laboratory, and these two cultures are implanted into surrogate females?

[Biology24123]

Thank you. Got a few qs:

1. Do we need to know about the types of stem cells? (totipotent, pluripotent, multipotent?) Or what about embryonic stem cells and somatic stem cells?

2. How much do we need to know about embryo splitting? Is it just that the embryo cells are split into two, using a think glass needle in the laboratory, and these two cultures are implanted into surrogate females?

1. Yes you need to know those three as well as the difference between Adult and embryonic stem cells

[adnauseam]

Pheremones- do they only act on same species, or different species?
thanks

[Biology24123]

Pheremones- do they only act on same species, or different species?
thanks

Same species

[cosine]

1. Yes you need to know those three as well as the difference between Adult and embryonic stem cells

can you give me the differences please?

[grindr]

Question was: which cells in the body are affected by a mutation that was inherited. (something like that)
I wrote germ line cells

Answer was gametes/sperm

Is this acceptable or not?

[pra96]

Question was: which cells in the body are affected by a mutation that was inherited. (something like that)
I wrote germ line cells

Answer was gametes/sperm

Is this acceptable or not?

Germline cells are the cells that become gametes, and hence any mutations in germline cells are passed onto gametes. But depending on the exact nature of the question, germline cells could be acceptable.

But given that gametes and germline cells are not the same thing, and depending on the exact question, the answer may have to be gametes. VCAA would probably only accept gametes as it is less vague than germline cells.

[sushibun]

Question was: which cells in the body are affected by a mutation that was inherited. (something like that)
I wrote germ line cells

Answer was gametes/sperm

Is this acceptable or not?

I would accept it
gametes and sperm differentiate from a germline cell
A germline cell might've had a mutation during DNA replication and this was passed down when it went through meiosis and produced gametes/sperm.

[pra96]

Hey could anyone explain the way in which the immune system rejects transplanted organs? in terms of t cells, b cells etc. Also the effect immunosuppressant drugs have on the immune system to stop rejection. pls 😢

[grindr]

Hey could anyone explain the way in which the immune system rejects transplanted organs? in terms of t cells, b cells etc. Also the effect immunosuppressant drugs have on the immune system to stop rejection. pls 😢

Immune system rejects transplanted organs through NK cells and Cytotoxic T cells. these cells check the markers on the transplanted cells, recognises them as foreign and then: Tc cells release perforin into the cell to puncture its membrane, NK cell tells the foreign tissue to lyse itself (I believe)

Immunosuppressant drugs work to repress the function of Ct cells so that they cannot reject the transplanted tissue. However it does suppress the whole immune system so the immune system of person is weaker

[Biology24123]

Immune system rejects transplanted organs through NK cells and Cytotoxic T cells. these cells check the markers on the transplanted cells, recognises them as foreign and then: Tc cells release perforin into the cell to puncture its membrane, NK cell tells the foreign tissue to lyse itself (I believe)

Immunosuppressant drugs work to repress the function of Ct cells so that they cannot reject the transplanted tissue. However it does suppress the whole immune system so the immune system of person is weaker

I just want to add that you don't need to know about suppressant drug specifically

[CarterGray12]

When talking about evidence relating to inheritance, are we allowed to say/should we say something is "proven"? I am somewhat hesitant writing it because with experimental design we can never say "proves" just that it "supports". For example, if an affected individual has no affected parents, would we write that it proves recessive or just supports it?

[cosine]

When talking about evidence relating to inheritance, are we allowed to say/should we say something is "proven"? I am somewhat hesitant writing it because with experimental design we can never say "proves" just that it "supports". For example, if an affected individual has no affected parents, would we write that it proves recessive or just supports it?

A hypothesis is never proven, never write proven. Always write,  'in order for the hypothesis to be supported, ....'

[grindr]

The answer is A.

I dont't understand why, could someone please help?

[cosine]

The answer is A.

I dont't understand why, could someone please help?

A. No trick here, simple as if you trigger the sensory hair, it's called 'sensory' hair suggesting that it's actually the receptor of the stimulus. So when the hair is stimulated, the action potential will be passed down to the motor neurone, and this will activate the effector muscles to retract. Also, no mention of the inhibitory neurone is mentioned when the sensory is activated, so no further conclusions can be made.
B. If you cut the sensory neurone at point J, then the stimulation would not be passed onto the motor neurone because it does not pass the point of J, so B is incorrect.
C. If the point K is cut, then the effect of the inhibitory neurone does not alter the function of the excitatory neurone, so there actually will be retraction.
D. If they are stimulated at the same time, then their effects would 'cancel' out because one actives and one inhibits, so they are like positive and negative, neutral.