Gametes produced in the process of meiosis in humans (chromosome 4)has a long and short arm the short arm has the gene for Huntington's (H) attached and the long arm the gene for Red hair (R)
state the differences in the product cells at telophase II if a crossing over had occured halfway between the Huntington gene and the centromere.
To understand the differences in the product cells at Telophase II after crossing over, let's first understand the basic concept of meiosis.
Meiosis is a specialized cell division process that occurs in the gonads (ovaries and testes) to produce haploid gametes (eggs and sperm) with half the number of chromosomes as compared to the parent cell. It consists of two rounds of division, namely Meiosis I and Meiosis II.
During meiosis, there is a phase called Prophase I, where homologous chromosomes, which are pairs of similar chromosomes, come together and can exchange genetic material through a process called crossing over.
Now, coming back to your question, where the gametes produced during meiosis in humans (chromosome 4) have a long and short arm. Let's assume that one chromosome 4 has the Huntington gene (H) on the short arm and the Red hair gene (R) on the long arm.
If a crossing over occurs halfway between the Huntington gene (H) and the centromere during Prophase I, it would result in the exchange of genetic material between the homologous chromosomes. This crossing over creates genetic recombination, resulting in the formation of new combinations of alleles on the chromosome.
At Telophase II, which is the final stage of meiosis II, the cells have undergone two rounds of division. Each cell contains half the number of chromosomes compared to the original cell. In this case, we are specifically looking at the chromosome 4.
If a crossing over occurred between the Huntington gene (H) and the centromere, two gametes will be produced. Let's consider the original chromosome with H on the short arm and R on the long arm as Chromosome 4A. The newly formed chromosome, resulting from crossing over, can be referred to as Chromosome 4B.
In one of the gametes, the chromosome will retain the original Chromosome 4A, which carries H on the short arm and R on the long arm. This is because crossing over occurred beyond the Huntington gene (H), so there was no exchange of genetic material in that region.
In the other gamete, the chromosome will contain Chromosome 4B, which carries a new combination of genetic material. It will have the short arm with R (originally from the long arm) and the long arm with H (originally from the short arm). This is because crossing over occurred halfway between the Huntington gene (H) and the centromere, resulting in the exchange of genetic material in that region.
So, to summarize, if a crossing over occurred halfway between the Huntington gene and the centromere during meiosis, the products cells at Telophase II would consist of one gamete with Chromosome 4A (H on the short arm and R on the long arm) and another gamete with Chromosome 4B (R on the short arm and H on the long arm) due to the exchange of genetic material between the chromosomes.