9. Mitosis and Meiosis

Horse diploid cells contain 64 chromosomes (2n = 64). How many chromosomes will be present in spermatogonium cells?

Horse diploid cells contain 64 chromosomes (2n=64). How many chromosomes will be present in primary oocyte cells?

Horse diploid cells contain 64 chromosomes (2n=64). How many chromosomes will be present in spermatids cells?

What is the correct term for the mature female gamete?

Contrast spermatogenesis and oogenesis. What is the significance of the formation of polar bodies?

During oogenesis in an animal species with a haploid number of 6, one dyad undergoes nondisjunction during meiosis II. Following the second meiotic division, this dyad ends up intact in the ovum. How many chromosomes are present in

(a) the mature ovum and

(b) the second polar body?

(c) Following fertilization by a normal sperm, what chromosome condition is created?

What is the probability that, in an organism with a haploid number of 10, a sperm will be formed that contains all 10 chromosomes whose centromeres were derived from maternal homologs?

Wolves and coyotes can interbreed in captivity, and now, because of changes in their habitat distribution, they may have the opportunity to interbreed in the wild. To examine this possibility, mitochondrial DNA from wolf and coyote populations throughout North America—including habitats where the two species both reside—was analyzed, and a phylogenetic tree was constructed from the resulting data. A sequence from a jackal was used as an outgroup, and a sequence from a domestic dog was included, demonstrating wolves as the origin of domestic dogs. What do you conclude about the possibility that interspecific hybridization occurred between wolves and coyotes on the basis of this phylogenetic tree?