The Biological Question Thread

[stonecold]

Gotta love questions like in VCAA 2006 about why the shrimp are the same species and then the answer is the are not the same species.  VCAA are so lame.

Actually, I think that VCAA have simply mis-worded their answer on the assessment report. The question was

"Why is the inability to mate sufficient evidence to call the two groups two different species?"

I think that VCAA meant that many students came up with the following response:

'because they cannot mate' --> 0/1

I think VCAA wanted the following answer:

'inability to mate implies inability to produce viable and fertile offspring, which is the criterion for calling two groups different species' --> 1/1

You messaged douchy about this didn't you? 

[thushan]

Yes! How do you know?

[Jdog]

hey thooozen,

get of VN and do some bio

and lol at your sig, im sure you would not be happy with 46 in boths or bio.

[stonecold]

hey thooozen,

get of VN and do some bio

and lol at your sig, im sure you would not be happy with 46 in boths or bio.

lol.  that is how I know.  you said he always pronounces your name wrong.

[thushan]

@ Jdog -> I am!

@ stonecold -> LOL. Always? He only mentioned me once!

[stonecold]

@ Jdog -> I am!

@ stonecold -> LOL. Always? He only mentioned me once!

Serious?  I swear I've heard your questions a few times, but I don't really pay much attention, so probably not haha...

[stonecold]

I'm a bit confused about the difference between incomplete dominance and co-dominance as I've heard many different opinions on the matter.
For example:
If you were to breed a white flower with a red flower and the offspring were all pink would VCAA call this incomplete dominance or co-dominance? My teacher at school says its incomplete as its a blend of the two, but I've also heard that it would be co-dominance because in effect both alleles are fully expressed because there are both red and white pigments they are just such small 'dots' they appear to be pink.

What are your thoughts?

Is your name actually ally?  because your username is gold if so

[Jdog]

no his name is thushan but douch pronounced it thooozen

[Allygator]

lol jdog,
i think he was referring to me
and yeah my name is ally

[stonecold]

lol jdog,
i think he was referring to me
and yeah my name is ally

haha that is awesome!  too clever :p

[sillysmile]

hopefully nobody gets freaked out by my very large assortment of questions:

1. How could I describe sticky ends and blunt ends?
2. Does DNA ligase anneal both covalent and hydrogen bonds?
3. Is an Adenovirus simply an alternative name for a Retrovirus?
4. Is a Bacteriophage a virus which infects bacteria?
5. What are some effective/common vectors for the genetic modification of plants?
6. What are the differences between a microsatellite and a STR? and are these sections of DNA mainly used fro DNA fingerprinting and profiling?
7. What is the main purpose of the southern blot technique?
8. Can both Substitution and Frameshift mutations be classified as Point mutations?
9. What exactly is Deamination and how can it cause a mutation?
10. What exactly is a Tautomeric shift and how can it cause a mutation?
11. Is comparative anatomy an evidence of evolutionary relationships?
12. Is Ribosomal RNA single stranded and linear?
13. Could random mating be a source of variation.
14. Can Sex-linked traits be either X-linked or Y-linked?



thank you, and as usual + karma to anybody who helps

[masonnnn]

1. sticky ends have a complementary overhang of bases allowing them to form hydrogen bonds so can 'stick' to the matching strand. Blunt ends are when both strands are cut at exactly the same point with no overhang so cannot be rejoined, more useful in gel electropherisis where you just want sections to be separate.

2. not a clue in the world...it sure does though. haha

3. I think retrovirus' contain RNA where as adenovirus' contain DNA, do we need to know that?

4. Nay, they're a virus that affect bacteria

5. Bacteria i think is the main one, i remember an exam question on this where they placed bacteria around a plant and the trick was that the infectious strand in the dna had to be removed so that it did not act as a vector

and that's a start for now, need to scoot.

[masonnnn]

misread question 2, i thought you said HOW does dna ligase anneal the bonds...
i'm relatively sure it re-joins the covalent(phosphodiester) bonds, yet i think the hydrogen bonds occur themselves b/w matching bases. not 100% positive

[sillysmile]

1. sticky ends have a complementary overhang of bases allowing them to form hydrogen bonds so can 'stick' to the matching strand. Blunt ends are when both strands are cut at exactly the same point with no overhang so cannot be rejoined, more useful in gel electropherisis where you just want sections to be separate.

2. not a clue in the world...it sure does though. haha

3. I think retrovirus' contain RNA where as adenovirus' contain DNA, do we need to know that?

4. Nay, they're a virus that affect bacteria

5. Bacteria i think is the main one, i remember an exam question on this where they placed bacteria around a plant and the trick was that the infectious strand in the dna had to be removed so that it did not act as a vector

and that's a start for now, need to scoot.

haha thank you, and I mistyped plants instead of bacteria for 4.

[Russ]

2. Does DNA ligase anneal both covalent and hydrogen bonds?
It joins the fragments, but the hydrogen bonds are a product of interaction between the 2 strands.

3. Is an Adenovirus simply an alternative name for a Retrovirus?
No. They're two different taxonomical virus families.

6. What are the differences between a microsatellite and a STR? and are these sections of DNA mainly used fro DNA fingerprinting and profiling?
microsatellites can be STRs, yes. and yes, pretty much, i've never heard of any other major uses

7. What is the main purpose of the southern blot technique?
Detection of nucleic acids (ie DNA sequences). There's also western blot etc.

8. Can both Substitution and Frameshift mutations be classified as Point mutations?
Point mutations are where there's only 1 base difference, so frameshift can't cause them.

9. What exactly is Deamination and how can it cause a mutation?
From the name, it's the removal of an amine group. It can occur to any molecule, not just DNA. When it happens in DNA, if not repaired it has altered the base sequence and thus the protein. The thing is, since the bases are similar, deamination can change one base to another...this won't be flagged by the inbuilt repair system of the body.

10. What exactly is a Tautomeric shift and how can it cause a mutation?
This is seriously on the course? Mao can give you a way better answer than me, since it's a chemical term but there are keto and enol forms of molecules and tautomeric shift is between them. When it happens in DNA -> mutation.

12. Is Ribosomal RNA single stranded and linear?
From memory, it's single stranded but it can form loops when complementary sequences match up. Can't remember if all the subunits do the same thing.

13. Could random mating be a source of variation.
It enables genetic variation in a population (why it's part of the HW preconditions) but I wouldn't describe it as a "source" of genetic variation. That's semantics though.

14. Can Sex-linked traits be either X-linked or Y-linked?
Yes, but X linked are way more common/interesting