VCE Biology Question Thread

[Rob16]

during DNA replication, does the enzyme DNA primase attach the RNA primers on the 3' end of the leading and various points on lagging strands or is it RNA primase that attaches it?

[vox nihili]

The question kinda implies/explicitly states that it's for a single gene. Don't try to be too fancy, especially on short answer questions just give the most logical answer as more obscure answers which may be correct may not be interpreted in the way you intend.

I agree. Certainly you're right AhNeon, in saying that polygenic inheritance could also produce an array of traits, but sometimes VCAA do expect students to exercise a little bit of commonsense. Why would they be looking at a gene locus with absolutely no relevance to the trait?

during DNA replication, does the enzyme DNA primase attach the RNA primers on the 3' end of the leading and various points on lagging strands or is it RNA primase that attaches it?

It's just called primase (if we wanted to be fancy we could call it a DNA-dependent RNA polymerase)

[AhNeon]

The question kinda implies/explicitly states that it's for a single gene. Don't try to be too fancy, especially on short answer questions just give the most logical answer as more obscure answers which may be correct may not be interpreted in the way you intend.

Thanks!
Btw, i've heard conflicting ideas on what stage of meiosis independent assortment occurs in. I would say Metaphase 1 as that's where the chromosomes actually orient themselves, but some trials have said anaphase 1

[Angelx001]

There are about twenty bandicoots (extinct or not) in the same family, Peramelidae. They share the similar features of long, pointed snouths and small ears. The eastern barred bandicoot, Permales gunnii and southern brown bandicoot, Isoodon obseulus, are currently found in the wild, but are under threat of extinction because of habitat destruction.

b. All bandicoots are marsupial and stated diverging into the different bandicoot species about 18 million years ago.
i. What fossil evidnece would be required to support this time of divergence?[/b][/b]

Please help me!

[Angelx001]

What does it mean by 'DNA mutates at a set rate'? I thought mutations occurred randomly?

[Angelx001]

Discuss the difference between the proteomes of the cardiac stem cells & the skin cells.

Thank you ^^

[Rob16]

If someone has the linked gene PQ/pq why is the genotype of the recombinant gametes only Pq and pQ? why can't it also be Pp or Qq?

[cosecant]

There are about twenty bandicoots (extinct or not) in the same family, Peramelidae. They share the similar features of long, pointed snouths and small ears. The eastern barred bandicoot, Permales gunnii and southern brown bandicoot, Isoodon obseulus, are currently found in the wild, but are under threat of extinction because of habitat destruction.

b. All bandicoots are marsupial and stated diverging into the different bandicoot species about 18 million years ago.
i. What fossil evidnece would be required to support this time of divergence?[/b][/b]

Please help me!

all transitional fossils containing features of both ancestral and descendant species found are dated to be 18 million years old

If someone has the linked gene PQ/pq why is the genotype of the recombinant gametes only Pq and pQ? why can't it also be Pp or Qq?

because recombinant gametes only arise from crossing over. Pp are alleles of the same gene, there must also be an allele for the other gene that is represented by q or Q.
PQ/pq indicates that on one of the homologous chromosomes there is a P and Q allele while the other chromosome of the homologous pair there is the p allele and the q allele. PQ and pq would be the parental gametes. So if crossing over did occur, Pq and pQ would result.

[Gogo14]

A questions shows a karyotype with an individual with just one x chromosome- turner syndrome.
It asks what stage did this non disjunction mutation occur in germline cells?

I wrote anaphase 2, but the answer says anaphase 1. Why? Could it also be anaphase 2?

[FatimaEl]

What does it mean by 'DNA mutates at a set rate'? I thought mutations occurred randomly?

Is this in regards to mitochondrial DNA, if so, mitochondrial DNA mutates at a constant rate, not sure about other types of DNA though, because from what i know mutations do occur randomly?

[Angelx001]

Is this in regards to mitochondrial DNA, if so, mitochondrial DNA mutates at a constant rate, not sure about other types of DNA though, because from what i know mutations do occur randomly?

Yeah, it was in reference to mtDNA. Thank you !! Had no idea mtDNA mutates at a constant rate- so does this depend on the individual or species?

[Angelx001]

What are "trans-membrane proteins"?

[sweetcheeks]

What are "trans-membrane proteins"?

They are proteins that span the entire length of the plasma membrane. Protein channels are an example of this.

[Gogo14]

Do we need to know how to calculate allele frequencies? Seen some qs on past exams, but not sure if still in study design

[Gogo14]

Does independent assortment occur in metaphse 1 or anaphase 1 of meiosis?