Biology Unit 3 Questions Megathread

[dooodyo]

Hey guys,

Just did a practice question and was wondering how many marks you guys would give this answer
out of a maximum of 2 I think.

Question: Different cell types have different sets of transport proteins. Explain.

My answer:
Transport proteins are very specific and only move certains solutes across the cell membrane. Since some cells can
be specialised to carry out particular functions they need to be able to exchange particular substances more so than
other cells.

Its a bit dodgy  . So I wanted to know how you guys would set out your answers so as to achieve full marks?

[dooodyo]

Anyone have VCAA 2001?

Any help much appreciated.

[HERculina]

Question: Different cell types have different sets of transport proteins. Explain.

My answer:
Transport proteins are very specific and only move certains solutes across the cell membrane. Since some cells can
be specialised to carry out particular functions they need to be able to exchange particular substances more so than
other cells.

Its a bit dodgy  . So I wanted to know how you guys would set out your answers so as to achieve full marks?

i would give this full marks
maybe give an example to make your answer better?

[dooodyo]

Hey,

What do you happen to mean by examples? Like cells in the respiratory
surfaces and etc ?

[HERculina]

hm well like
For example, liver cells would have large amounts of carrier proteins specifically pumping in glucose molecules?
...something like that   

[HERculina]

i have a question about protein structure:
the beta sheets in the secondary structure - are the Hydrogen bonds between two polypeptide chains. and does this mean beta sheets only exist in proteins with quaternary structures?
im so confused :|

[WhoTookMyUsername]

yeah i saw that description somewhere. Its inaccurate, what it means is 'two portions of the same polypeptide chain' so its the same chain with a bend pressed against itself

[HERculina]

ohhh ok thanks for clearing that up!

[Russ]

Question: Different cell types have different sets of transport proteins. Explain.

My answer:
Transport proteins are very specific and only move certains solutes across the cell membrane. Since some cells can
be specialised to carry out particular functions they need to be able to exchange particular substances more so than
other cells.

Its a bit dodgy  . So I wanted to know how you guys would set out your answers so as to achieve full marks?

My answer would be:

Different cell types have different functions and, as such, have different requirements. Transport proteins exist to enable a cell to access the molecules required for its function and, for this reason, will differ between cell populations.

Your answer was good, just focus on fixing the wording because it was a little clunky

[dooodyo]

Hey Russ,

I was wondering how would you structure your answers any guide as
of such ?

[poojas73]

can someone please explain the action of gravity and auxin on root cells? i'm not really understand it

[jbebbo]

I haven't done that well in SA but i am improving

me too. i just did the VCAA 2008 this morning, and i didnt do well in SA too. they are hard =(

I did 2009 and yes, the MC is MUCH easier, i got 25/25 for MC and 40/50 for SA 87%

I'm quite happy with that, and i learnt a lot which was great.
Made a few silly mistakes, and didn't know some of the stuff

I do have a few concerns though

I can't seem to spend long enough on practice exams, i'm always finished within an hour even though i'm trying to slow myself down. Is this the same for everybody?


This was an MC Q that i'm confused about a bit

Q 11) Human and plant hormones are similar in that all are :

C) Signalling molecules that act on receptor molecules
D) Transported around the organism by a circulating fluid.

I know that C is correct, but why is D wrong, i was of the belief that hormones in plants were circulated in the phloem?

Also , when writing a scientific experiment, is your hypothesis taken directly from the question? Are you not allowed to extrapolate so that, instead of testing the effect of an enzyme or substance in an animal, you aren't able to take it out and place it in a test tube?

(that's what answers seemed to suggest)

Hey Bazza16!
Option D is wrong because some plant hormones (e.g. auxin) undergo either apoplastic or symplastic transport - essentially being transported through the cell wall and the space between the cells, and through the cytoplasm of the cell, respectively.

[Russ]

Hey Russ,

I was wondering how would you structure your answers any guide as
of such ?

I don't really have a guide for it but I tend to start by making a statement and then explaining that statement in subsequent sentences. I can get out some of my sample questions/answers if you want but *shrug*

[WhoTookMyUsername]

As endocrine cells/glands are 'ductless' does that mean the hormones are just released through diffusion etc. ?

Also, what exactly is a cellular/ organ duct

[Russ]

It's an anatomical term/definition but it's just a channel leading to/from an organ.

Endocrine glands secrete directly to the blood but not necessarily through diffusion