VCE Biology Question Thread

[Gogo14]

When is an ideal and reasonable time for the teachers to finish covering the content and start exam revision?

[vox nihili]

When is an ideal and reasonable time for the teachers to finish covering the content and start exam revision?

Vexed question, it depends on the student and the class. I don't think there's a whole lot wrong with any finishing time to be honest. You should be starting exam revision now anyway, including dealing with the new content too

[HasibA]

When is an ideal and reasonable time for the teachers to finish covering the content and start exam revision?

i reckon end of this term/start of holidays- where are you upto? pretty sure you should be good as long as you finish the course before or during the holidays

[Gogo14]

Well gg. My class is only up to inheritance and still need to finish sac 1.

[HasibA]

Well gg. My class is only up to inheritance and still need to finish sac 1.

my class is on inheritance too- chill, you've got this. work ahead if you can but overall you should be fine i think my class starts evolution next week or something, no need to stress. plus im assuming its your only 3/4 (year 11?)

[blacksanta62]

Hey guys, I have a SAC tomorrow and I would love some insight with these questions:
1)What is an advantage and a disadvantage of introducing crops which genetically modified to grow in saline or poorly aerated soils?
2)What is the point of genetic engineering? Could anyone give me a concise definition?
3) What is a gene probe? How is it used? Mention autoradiography in your answer
Is this a suitable answer, the book goes into a lot of depth: Gene probes are single standed DNA or RNA which can locate a specific DNA fragment. Once located, the probe is joined to the fragment because it is complementary and is 'labelled' by a radioactive marker which allows for the location of the target fragment
Do I need to mention gel electrophoriesis? The answer does
Thank you

[Gogo14]

Why does apoptosis for non disjuction not occur in meiosis? Isn't there a spindle attachment checkpoint at the end of metaphase, or is that just for mitosis?

my class is on inheritance too- chill, you've got this. work ahead if you can but overall you should be fine i think my class starts evolution next week or something, no need to stress. plus im assuming its your only 3/4 (year 11?)

Yep, thnx

[vox nihili]

Why does apoptosis for non disjuction not occur in meiosis? Isn't there a spindle attachment checkpoint at the end of metaphase, or is that just for mitosis?

Interesting question, well beyond VCE.

I'm not really sure. My suspicion is because it's a different non-disjunction. It's not that the chromatids have failed to split, but the homologues have failed to split. One would assume that the regulatory apparatus for each is slightly different.

[HasibA]

are we expected to be able to do dihybrid test crosses? not just determination of hetero/homo, moreso complex questions?

[Mapleflame]

are we expected to be able to do dihybrid test crosses? not just determination of hetero/homo, moreso complex questions?

The SAC is supposed to just have monohybrid- though I haven't done it yet. Just familiarise yourself with the concept in case you need it, but I don't think working out a dihybrid punnet square would ne needed.

[Mapleflame]

Hey everyone! I'm currently doing Chapter 10 from the Nelson textbook and I came across this question which I have no idea how to answer. Would someone please be able to help me out?

Question: Chicken-sized dinosaurs with very large optic lobes have been found on the southern coast of Australia. What does this tell us about conditions in this location at the time that these animals were alive?

Thank you in advance!

The smaller size of an animal allows for them to A) hide from predators, especially larger ones, and B) easier access to grounded food sources (under tree roots, etc.) which would mean that there were large predators in the area, and plenty of ground-food.
The optical lobe is the primary vision cortex; a larger one in these creatures would give it an advantage in sight and imagery processing, so it was probably either nocturnal, or needed fast reflexes and processing.
To summarise these points, the conditions were most likely in a forested area or desert (due to pockets at ground level to hide in/scavenge in) with larger predators. The creature is also possibly nocturnal.

Hope this helped.
~A.H

[blacksanta62]

Hey guys, I have a SAC tomorrow and I would love some insight with these questions:
1)What is an advantage and a disadvantage of introducing crops which genetically modified to grow in saline or poorly aerated soils?
2)What is the point of genetic engineering? Could anyone give me a concise definition?
3) What is a gene probe? How is it used? Mention autoradiography in your answer
Is this a suitable answer, the book goes into a lot of depth: Gene probes are single standed DNA or RNA which can locate a specific DNA fragment. Once located, the probe is joined to the fragment because it is complementary and is 'labelled' by a radioactive marker which allows for the location of the target fragment
Do I need to mention gel electrophoriesis? The answer does
Thank you

Bump

[vox nihili]

Hey guys, I have a SAC tomorrow and I would love some insight with these questions:
1)What is an advantage and a disadvantage of introducing crops which genetically modified to grow in saline or poorly aerated soils?
2)What is the point of genetic engineering? Could anyone give me a concise definition?
3) What is a gene probe? How is it used? Mention autoradiography in your answer
Is this a suitable answer, the book goes into a lot of depth: Gene probes are single standed DNA or RNA which can locate a specific DNA fragment. Once located, the probe is joined to the fragment because it is complementary and is 'labelled' by a radioactive marker which allows for the location of the target fragment
Do I need to mention gel electrophoriesis? The answer does
Thank you

1. You could probably try this one out first.

2. Again, what do you think? This isn't a question that requires a definition. I'd really try to stick away from remembering definitions. You'd do much better to remember concepts instead.

3. Autoradiography does usually involve gel electrophoresis, but I don't think that's an acceptable question for VCE level, so I wouldn't worry about it. Be more specific about the molecular level with probes and then that answer should come together nicely (e.g. you should speak about the complementary binding of the probe to its target sequence). I'd also probably tighten up the "labelled" part of the answer; because it seems to suggest that you don't really know what that means (which may or may not be the case, it just looks like that!)

[HasibA]

any tips for working out a pedigree / shortcuts? i remember reading some like 'if the parents have offspring whose phenotype is different to both their parents, then that offspring is recessive to that trait, either being affected by it adversely or not'.
(hope this made sense xD) thanks!

[Gogo14]

any tips for working out a pedigree / shortcuts? i remember reading some like 'if the parents have offspring whose phenotype is different to both their parents, then that offspring is recessive to that trait, either being affected by it adversely or not'.
(hope this made sense xD) thanks!

Every chart will be different but here are just some GENERAL key features that will help you identify pedigrees. These hints MAY indicate the disease
Recessive:
- can skip generations
-2 unaffected can have an affected offspring
Dominant:
-Each generation
-unaffected+affected can have affected offspring
Autosomal:
-probably easier to prove that it is not x linked
-even gender ratios
X linked:
-uneven gender ratios (X recess)
-male passes on to all daughters (x dom)

Just general advice, but you should always work it out logically than following "shortcuts"