Genetics Answers

The common housefly has a haploid number of 6 consisting of 3 long chromosomes (one

metacentric, one acrocentric, and one telocentric); 3 short chromosomes (one metacentric,

one acrocentric, and one telocentric). Draw and label a typical housefly primary spermatocyte

in Metaphase I and spermatozoa at Telophase II.

The common housefly has a haploid number of 6 consisting of 3 long chromosomes (one

metacentric, one acrocentric, and one telocentric); 3 short chromosomes (one metacentric,

one acrocentric, and one telocentric). Draw and label a typical housefly primary spermatocyte

in Metaphase I and spermatozoa at Telophase II.

An XXX individual may be result of an abnormal complement of chromosomes in the egg or sperm. At what point of meiosis does this abnormality arise in female and males? What is it due to? Make use of diagrams to explain your answer

a. A primary spermatocyte has the genotype AaBbee. The A and B loci are linked in cis configuration on the long arm of an acrocentric chromosome. The E locus is on a metacentric chromosome. Show the chromosomes containing these genes at metaphase I telophase I and telophase ii using diagrams. Diagrams must clearly labelled

B. Using information in a) show the resulting telophase I and telophase ii diagrams after a crossover between the A and B locus has occured at Pachytene of meiosis. Diagrams must be clearly labelled

An important function of meiosis is to reduce the chromosome number to exactly half. How is this done? What makes such a process necessary

A primary spermatocyte has the genotype DdEe. These genes assort independently at meiosi

I. Show the chromosome containing these genes Metaphase I telophase I and telophase ii usingdiagrams. Diagrams must be clearly labelled and show metacentric chromosomes undergoing meiosis

Variable expressivity, in contrast to penetrance, occurs when an individual has the allele in question and is clinically affected

A primary spermatocyte has the genotype AaBbee. The A and B loci are linked in cis configuration on the long arm of an acrocentric chromosome. The E locus is on a metacentric chromosome. Show the chromosomes containing these genes at Metaphase I, Telophase I and Telophase II using diagrams. Diagrams must be clearly labelled.​​​

genes

In mice, the allele C for colored fur is dominant over the allele c for white fur, and the allele V for normal behavior is dominant over the allele v for waltzing behavior, a form of discoordination. Give the genotypes of the parents in each of the following crosses.

Colored, normal mice mated with white, normal mice produced 29 colored, normal and 10 colored waltzing offspring.