VCE Biology Question Thread

[Angelx001]

"What is meant by the diploid chromosome number?" (1 mark)
My answer: Diploid chromosome are homologous pairs which have identical gene loci.

Is this correct?

[The Usual Student]

"What is meant by the diploid chromosome number?" (1 mark)
My answer: Diploid chromosome are homologous pairs which have identical gene loci.

Is this correct?

it says 'THE" diploid chromosome number so it may be referring to the number of chromosomes in a normal body cell which contains homologous pairs of chromosomes ( AKA 2n).

edit: I worded it badly, " the number of chromosomes in a normal somatic cell that includes twice the number of chromosomes in a haploid cell ( 2n) and both sex chromosomes"
^^^ i reckon that is better

[anniebrejcha]

Yeah non-competitive is usually permanent but I found some examples that are not. I think it is an ok assumption to just say the majority of them are permanent.

ok cool thankyou very much!!

also (im just getting any remaining silly questions out there before the exam);
why do homologous chromosomes pair during meiosis and not mitosis? 

[The Usual Student]

ok cool thankyou very much!!

also (im just getting any remaining silly questions out there before the exam);
why do homologous chromosomes pair during meiosis and not mitosis?

no problem!
The aim of meiosis is to produce 4 haploid gametes that are genetically different whilst in mitosis the aim is to produce 2 genetically identical daughter cells ( unless a mutation was to occur ).
Hence, the homologous chromosomes must be separated during meiosis so each of the 4 daughter cell can receive at least one copy of the chromosome. Whilst in mitosis, the two duaghter cells will have a haploid number of chromosomes and hence the homologous pairs of chromosomes do not need to be separated
* you could also answer this question from a variation point of view and argue that homologous chromosomes need to be paired from crossing over to occur. Wasn't sure which way to go :/

[dosh24]

no problem!
The aim of meiosis is to produce 4 haploid gametes that are genetically different whilst in mitosis the aim is to produce 2 genetically identical daughter cells ( unless a mutation was to occur ).
Hence, the homologous chromosomes must be separated during meiosis so each of the 4 daughter cell can receive at least one copy of the chromosome. Whilst in mitosis, the two duaghter cells will have a haploid number of chromosomes and hence the homologous pairs of chromosomes do not need to be separated
* you could also answer this question from a variation point of view and argue that homologous chromosomes need to be paired from crossing over to occur. Wasn't sure which way to go :/

I don't think it is correct to say that the aim is to produce 4 haploid gametes in meiosis as for females only one egg is produced for each germ-line cell due to polar bodies. It would be safer to say that meiosis produces genetically different gametes that are haploid.

[The Usual Student]

I don't think it is correct to say that the aim is to produce 4 haploid gametes in meiosis as for females only one egg is produced for each germ-line cell due to polar bodies. It would be safer to say that meiosis produces genetically different gametes that are haploid.

probably so,
Does that mean the process of meiosis is different in men and women? as in the anaphase 1 and telophase 1 and anaphase 2 ect stuff is all different in women?
I thought it was the same process but instead of 4 gametes it is 1 gamete and 3 polar bodies, if it is the case of them being the same then you could still argue the initial idea but swap the wording around

In hindsight the genetic vairation idea was probably what they wanted though, can someone answer my question above? ^^^^^

[anniebrejcha]

no problem!
The aim of meiosis is to produce 4 haploid gametes that are genetically different whilst in mitosis the aim is to produce 2 genetically identical daughter cells ( unless a mutation was to occur ).
Hence, the homologous chromosomes must be separated during meiosis so each of the 4 daughter cell can receive at least one copy of the chromosome. Whilst in mitosis, the two duaghter cells will have a haploid number of chromosomes and hence the homologous pairs of chromosomes do not need to be separated
* you could also answer this question from a variation point of view and argue that homologous chromosomes need to be paired from crossing over to occur. Wasn't sure which way to go :/

thanks again, i appreciate all your help so so much. that clears it all up a tonne.

[homosapien]

Do you think we need to know a lot about chromosomal mutations?
e.g. translocations, non-disjunction
I am not very strong in these areas but i dont remember seeing them in any past vcaa exams? maybe ive just forgotten

[homosapien]

Where are mast cells produced?
They are found in connective tissue but where are they actually produced / what produces them?

[The Usual Student]

Do you think we need to know a lot about chromosomal mutations?
e.g. translocations, non-disjunction
I am not very strong in these areas but i dont remember seeing them in any past vcaa exams? maybe ive just forgotten

non-disjunction is relevant but i dont think translocation is a big concept to be familiar with

[thuynh]

What are regulator genes exactly.... And how does it relate to gene regulation?

[The Usual Student]

What are regulator genes exactly.... And how does it relate to gene regulation?

A regulator gene is a gene that produces a regulator protein or molecule. If the regulator gene is expressed, the regulator protein/molecule will be synthesized and that binds to the "operator" which stops RNA polymerase from constructing a mRNA for the gene we are discussing.

That is how it regulates genes, if the RG is expressed, we can't build mRNA to copy the gene but if an inducer molecule is present it can bind to the regulator protein which stops it from stopping the mRNA.

[hodang]

Thank you so much AhNeon and asini

[hodang]

Anyone know a good definition for lysosome and rough ER?

Help us Much appreciated 😅

[Gogo14]

Where are mast cells produced?
They are found in connective tissue but where are they actually produced / what produces them?

I think all blood cells are produced in the bone marrow

Anyone know a good definition for lysosome and rough ER?

Help us Much appreciated 😅

Lysosome- vesicle containing digestive enzymes
Rough ER- a transport system where secretory protein synthesis occurs