Female: +; N = 1 Male: W; N = 1 Q Select to Mate ୪ Q Select to Mate

Why are polyandrous mating systems more rare than polygynous matings? Only males are capable of multiple rounds of reproduction within a single breeding season Only females care for the young Females usually experience more intrasexual selection pressure than males Females usually devote more energy to offspring production and development.

Figure 12.6 What are the genotypes of the individuals labeled 1, 2, and 3?

Refer to question 4. Assuming complete dominance, the F2 generation will show a phenotypic ratio of _______. a.3:1 b.9:1 c. 1:2:1 d. 9:3:3:1

Figure 12.12 What ratio of offspring would result from a cross between a white-eyed male and a female that is heterozygous for red eye color?

________ in a trait is indicated by a bell curve.

Mutations Can Uncouple Chromosomal Sex from Phenotypic Sex Give an example of a situation in which genetic sex, gonadal sex, and phenotypic sex do not coincide. Explain why they do not coincide.

Human females have two X chromosomes (XX); males have one X and one Y chromosome (XY). a. With respect to X chromosome alleles, how many different types of gametes can a male produce? b. If a female is homozygous for an allele on an X chromosome, how many types of gametes can she produce with respect to that allele? c. If a female is heterozygous for an X chromosome allele, how many types or gametes can she produce with respect to that allele?

Human females have two X chromosomes (XX); males have one X and one Y chromosome (XY). a. With respect to X-linked alleles, how many different types of gametes can a male produce? b. If a female is homozygous for an X-linked allele, how many types of gametes can she produce with respect to that allele? c. If a female is heterozygous for an X-linked allele, how many types of gametes can she produce with respect to that allele?

Assume that the ratio of females to males is 1:1. A couple already has two daughters and no sons. If they plan to have a total of six children, what is the probability that they will have four more girls? (a) (b) (c) 116 (d) 132 (e) 164