Please could someone help me been trying to make sense of a question in my assignment, really struggling at the moment.

question is

Gametes are produced in the process of meiosis. In humans, one pair of autosmes (chromosome 4) has a short arm and a long arm. On the short arm is a gene for Huntington disease (H) and on the long arm is a gene for red hair (R).

Draw a labelled diagram to show the chromatids of a diploid cell at the end of anaphase 1 of meiosis, for a person who is heterozygous for both characters.

I have a sketch of my pair autosomes but I am not sure whether both are labelled H and R or H
and R on one and h and r on other. I also have produce a second diagram to show product cells derived from this cell at telophase II asssuming there is no crossing over. Finally I have to state what diifferences there would be in the product cells at telophase II if
there had been a crossing over at a position halfway betwwen the Huntingdon disease gene and the centromere.

I am really desparate to understand this, if someone could just talk me through it I would be so very very grateful.

both capital letters of H and R are duplicated on one chromosome and lower case on the other - this is before crossing over occurs at prosphase 1

Thank you

Sure! I'd be happy to help you understand the question and guide you through the process of answering it.

First, let's break down the question into smaller parts.

1. Draw a labelled diagram to show the chromatids of a diploid cell at the end of anaphase 1 of meiosis, for a person who is heterozygous for both characters.

To start, you need to understand that during meiosis, chromosomes duplicate and go through two rounds of division, resulting in four haploid cells. Anaphase 1 is the stage where the homologous pairs of chromosomes separate.

In this case, you are dealing with one pair of autosomes (chromosome 4) that has a short arm and a long arm. On the short arm is a gene for Huntington disease (H) and on the long arm is a gene for red hair (R).

Since the person is heterozygous for both characters, it means they have one allele for Huntington disease (H) and one allele for red hair (R).

The two chromatids of each chromosome will have different versions of the gene:

- One chromatid will have the allele for Huntington disease (H) and the allele for red hair (R).
- The other chromatid will have the allele for no Huntington disease (h) and the allele for no red hair (r).

So, in your diagram, you should label one chromatid with H and R, and the other chromatid with h and r.

2. Draw a second diagram to show the product cells derived from this cell at telophase II assuming there is no crossing over.

At telophase II, the cells have undergone the second round of division, resulting in the formation of four haploid cells. Remember, telophase II follows anaphase II, where the sister chromatids of each chromosome separate.

Since there is no crossing over, the chromosomes should segregate independently.

In your diagram, you can show the four product cells, and make sure to indicate that each cell contains one copy of each chromosome. Label each chromatid with the appropriate allele combination (HR, hR, Hr, hr).

3. State the differences in the product cells at telophase II if there had been a crossing over at a position halfway between the Huntington disease gene and the centromere.

Crossing over is the exchange of genetic material between homologous chromosomes during prophase I of meiosis. If crossing over occurs, it can result in the recombination of alleles on different chromatids.

In this case, the crossing over is said to happen halfway between the Huntington disease gene (H) and the centromere.

If crossing over occurred, the chromatids would exchange genetic material. This means that new combinations of alleles may be formed. For example, a chromatid that initially had HR could end up with Hr after crossing over. The same applies to the other chromatid.

In your diagram, you would need to show the new combinations of alleles that resulted from crossing over.

I hope this helps clarify the question for you! If you have any further doubts or need additional assistance, please let me know.