VCE Biology Question Thread

[Rishi97]

Presumably the developmental proteins that go on to make sex structures are activated/deactivated at particular temperatures. Thus, the incubation temperature determines which set of proteins is activated and which sex is created.

Oh yeah that makes sense... Thanks for answering my weird questions Mr T-Rav I really appreciate it

[RazzMeTazz]

When defining independent assortment would it be sufficient to say: The disjunction of homologous chromosomes in anaphase 1 of meiosis is not influenced by the behavior of other pairs of homologous chromosomes.

Or would I have to include something about the alleles for genes as well, being able to separate independently into the gametes?

[RazzMeTazz]

Could someone please explain what is meant by the term 'segregation of alleles' and how this is different to 'independent assortment'?

Thanks!

[grannysmith]

When defining independent assortment would it be sufficient to say: The disjunction of homologous chromosomes in anaphase 1 of meiosis is not influenced by the behavior of other pairs of homologous chromosomes.

Or would I have to include something about the alleles for genes as well, being able to separate independently into the gametes?

I'd probably just describe it as: there is an equal chance for each chromosome of each homologous pair to end up on either side of the cell equator (and thus either daughter cells) as their orientation is random. Leads to genetic variation.

[vox nihili]

Oh yeah that makes sense... Thanks for answering my weird questions Mr T-Rav I really appreciate it

No point doing a science if you're not going to ask those questions

[Reus]

Could someone please summarise/simplify what gene therapy is?

So confusing haha' 

[Rachelle]

Why do centromeres duplicate in meiosis?

[alondouek]

Why do centromeres duplicate in meiosis?

In short, because you need two of them

The point of meiosis/mitosis is pretty much to duplicate genetic material, and you need a centromere to link sister chromatids as a component of the chromosome. Without the centromere, the genetic material cannot be compacted into the supercoiled state that is the chromosome.

[Reus]

Why do centromeres duplicate in meiosis?

Just think of chromosomes duplicating. Centromeres are a feature of a chromosome, hence duplicated. 

[grannysmith]

When does independent assortment occur? Metaphase or anaphase?

[nerdmmb]

When does independent assortment occur? Metaphase or anaphase?

Metaphase ( I think ) because that's when they align.

[RazzMeTazz]

At telophase of mitosis, would you consider the parent cell to have 46 chromosomes and 92 chromatids of 46 chromosomes and 46 chromatids (as a new nuclear envelope has formed around the two newly formed nuclei) ?

[theBRENDAN97]

Could i please have some help.
I'm struggling to differentiate in meiosis when the chromosomes become chromatids, chromatin, and then chromosomes again?
Is this the same for mitosis?
And in Metaphase I do the homologous chromosomes attach their centromeres to the spindles or is it the kinetochore (in Anaphase I)?
Appreciate any clarification.

[nerdmmb]

Can the promotor region of a DNA molecule bed defined as coding regions in the DNA molecule which activates transcription?

What would be a better definition?

Thanks!

[Cham]

Does DNA replication occur in mitosis?