Question

BIO QUESTIONS:

1. Explain why being a dominant allele does NOT mean that the allele is more common or more frequent in a population.

2. When exactly do animal cells become haploid during gamete formation? Be specific.

Why is it important for sexually reproducing organisms to have haploid gametes?

3. Horses and donkeys can hybridize to create a mule, which has some good qualities of both horses and donkeys. Horses somatic cells have 64 chromosomes while donkey somatic cells have 62.

What is the chromosomal number for the gametes of horses? Of donkeys? What is the diploid number for the somatic cells of a mule?

Using what you know about meiosis, why is it likely that mules cannot produce their own gametes but they CAN produce somatic cells (body cells) just fine?

Answer 1

1. Dominant traits have no reason to be common traits in a population, whether the trait is common in a population is determined by how many copies of a particular allele is carried in a population, it has nothing to do with the dominant and recessiveness of the allele. In populations, dominant genes have no predominance over other people's recessive genes unless people with those dominant genes get married. Dominant does not mean common in any way.

2. Animal cells undergo the development of haploidy during gamete formation during meiosis first divison, which is responsible for reducing the chromosome number by half.

It is important for sexually reproducing organisms to have haploid gametes as the sperms and eggs fuse together to give rise to a new individual with 46 chromosomes as then the chromosome number in an individual will be reestablished. The gametes have 23 chromosomes each.If the number of chromosomes would not have been haploid in the gametes, then the number of genes in an organism would have been doubled, which could be fatal for the organis.

3. The chromosome number of gametes in horses are 32 and that of donkeys are 31. Mules have 63 diploid chromosomes.

Mules chave chromosomes from donkeys and horses and as these are two different organisms, the chromosomes are quite different and they do not match, because of an odd number of siploid chromosomes, the sperms and eggs cannot find their partners, causing them not to be made. Somatic cells divide by a process called mitosis and mitosis is concerned with maintaining an equal number of chromosomes. Somatic cell division is not concerned with matching up of chromosomes and segregation.