Most of the human disorders e.g Turner's syndrome occur due to errors that lead to a change in the number chromosomes. This error happens during.. ..when homologous chromosomes or sister chromatids fail during meiosis.

a. What is the diploid number of chromosomes for a human? b. What is the haploid number of chromosomes for a human? Which cells are considered diploid, gametes or somatic cells? C. d. Which cells are considered haploid, gametes or somatic cells?

Draw a diagram of meiosis in a cell where 2n = 6, in a case where there is interchromosomal mixing. Use a clearly labelled colour code (what does each colour represent?) to represent the chromosomes.

2.4

In fruit flies, chromosomal crossing over does not occur in meiosis in males, whereas crossing over does occur in meiosis in females. In fruit flies that are heterozygous at many genes (i.e. many maternal and paternal versions of the genes differ), at what stage would cells no longer be heterozygous for any gene during the process of meiosis? a)After the second meiotic division in males, and after the first meiotic division in females. b)After the second meiotic division in both males and females. c)After the first meiotic division in both males and females. d)After the first meiotic division in males, and after the second meiotic division in females.

. A mature female wolf, with 78 diploid chromosomes in each somatic cell, produces haploid oocytes (egg cells) containing how many chromosomes per cell? 1 sex-determining chromosome (Y) and 38 autosomes 2 sex-determining chromosomes (XX) and 76 autosomes 1 sex-determining chromosome (X) and 39 autosomes 2 sex-determining chromosomes (XY) and 76 autosomes 1 sex-determining chromosome (X) and 38 autosomes