VCE Biology Question Thread

[melons]

What is the best way to differentiate between X-linked recessive traits and X-linked dominant traits in pedigree analysis?

Thanks

If a daughter has a X-linked recessive condition, the father must have it as she will inherit his X chromosome. If it is X-linked dominant, any son who expresses the trait must have a mother with the trait as he receives the faulty chromosome from her and she must also express it as it is a dominant.

[tm_17]

In a monohybrid cross when you cross a heterozygous parent (Ff) with a homozygous parent (ff), you get a punnet square with the the first generation F1 (Ff, Ff, ff, ff).Right?
But i am a little confused with how you determine F2 from the offspring. Like would you use Ff or ff?   
Please explain. Thanks

[melons]

In a monohybrid cross when you cross a heterozygous parent (Ff) with a homozygous parent (ff), you get a punnet square with the the first generation F1 (Ff, Ff, ff, ff).Right?
But i am a little confused with how you determine F2 from the offspring. Like would you use Ff or ff?   
Please explain. Thanks

As far as I've seen, you don't normally need to do that...
It's normally two homozygous (FF x ff), then cross two F1 (Ff x Ff) to get F2.
If they asked something like that you would expect them to give more detail on which two to cross.

[katiesaliba]

With DNA sequencing, how is the template strand isolated in the first place? I presume that the DNA sample would go through PCR, be denatured, and then have a probe added to the solution to isolate the template strand?

[tm_17]

As far as I've seen, you don't normally need to do that...
It's normally two homozygous (FF x ff), then cross two F1 (Ff x Ff) to get F2.
If they asked something like that you would expect them to give more detail on which two to cross.

Oh okay then. Thanks for your help! 

[dankfrank420]

Can someone explain the difference between the template strand and the coding strand in protein synthesis.

[RazzMeTazz]

Does water have a high heat capacity, due to the H-bonds between water molecules being able to store and absorb relatively large amounts of thermal energy?

[Reus]

Does water have a high heat capacity, due to the H-bonds between water molecules being able to store and absorb relatively large amounts of thermal energy?

Yes!!

Sure this isn't a chemistry question?

[RazzMeTazz]

Can someone please explain the difference in function, between glycoproteins and glycolipids?

[RazzMeTazz]

Yes!!

Sure this isn't a chemistry question?

Haha yeah i admit it does relate to chemistry more than biology.. but it was on one of my biology handouts from earlier this year so I thought I would clarify :p

[grannysmith]

What are the products of anaerobic breakdown of glucose in animal cells? <---------- is it wrong to say pyruvate instead of lactic acid?

[nhmn0301]

What are the products of anaerobic breakdown of glucose in animal cells? <---------- is it wrong to say pyruvate instead of lactic acid?

You should say lactic acid not pyruvate. Glycolysis can continue without O2, but as it continues, pyruvate and NADH will also start to build up as they are no longer consumed by the Krebs Cycle or Electron transport chain. And hence this will ultimately slow down Glycolysis and if we want to continue Glycolysis, we need to remove pyruvate by doing fermentation. For animal for eg: what fermentation does it converting 2pyruvate + 2 NADH -> 2 lactic acid + NAD+

[Sense]

Do we need to remember how old the geological periods are? (Carboniferous, Triassic etc.)

[Sense]

http://www.vcaa.vic.edu.au/Documents/exams/biology/2008biol2-w.pdf

Can someone tell me why the answer to question 14 in this is C? I've checked the solutions and it still doesn't make sense?

[melons]

http://www.vcaa.vic.edu.au/Documents/exams/biology/2008biol2-w.pdf

Can someone tell me why the answer to question 14 in this is C? I've checked the solutions and it still doesn't make sense?

Both parents are heterozygous as they have a child with the condition, but don't express the trait themselves. By doing a punnet square we know that they have a 1/4 of homozygous dominant, 1/4 of homozygous recessive and 1/2 of heterozygous offspring. We know that III-3 is not homozygous recessive as they do not express the trait. Hence, there are two possible outcomes: she is homozygous dominant (1/3) or heterozygous (2/3) as the Punnett square has only three squares which are 'viable'. So the probability that she is Pp is 2/3 and the answer is C.