10.3 the fol (a) AB (b) A (c) B 10.4 Suppose that a family has five children. Find the probability that there are four girls and 10.5 Suppose that a family has five children. Find the probability that there are exactly three 10.6 Using only four genes denoted by (N-P-M-G), how many different boy One a girls and two boys. gene orders are 10.7 Suppose that you want to plant four trees in a plot and can choose from 10 different species. How many ways can be chosen to plant the trees in the plot? there? 10.8 Suppose that there are five types of toppings to put on a certain pizza. If you want to have only two toppings, how many choices do you have? 10.9 In plants and animals that sexually reproduce, each parent gives half of its genes to the offspring. Somatic cells contain two unique copies of each chromosome, and the two COpies of each chromosome form a chromosome pair, or homologous chromosomes. During the process of meiosis, the somatic cell will divide into gametes, or sex cells, each of which contains only one copy of each chromosome. (a) The common fruit fly has four different chromosomes; thus, in each somatic cell, there are eight chromosomes arranged in four pairs. How many unique gametes can one fruit fly form? (b) Humans have 23 different chromosomes; thus, in each somatic cell, there are 46 chromosomes arranged in 23 chromosome pairs. How many unique gametes can one human form? 10.10 Achondroplasia is a type of dwarfism caused by the presence of the dominant allele D on the gene. However, genotype DD is not viable and usually causes death before birth. Thus, a dwarf will have genotype Dd, while a nondwarf will have genotype dd. If a dwarf and nondwarf mate, what is the probability that their first child will be a nondwarf? 10.11 In Example 10.4, we saw that Mendel's pea plants had two colors of flowers: purple and white. On the gene for flower color, the purple allele, P, is dominant, while the white allele, p, is recessive. (a) If a heterozygous pea plant with purple flowers is crossed with a pea plant with white flowers, what proportion of pea plants in the next generation will have white flowers? There are some flowering plants for which the combination of two alleles can express three different phenotypes. For example, for some plants, flower color is determined by two alleles, R and r, where RR flowers are red, Rr flowers are pink, and rr flowers are white. (b) If a plant with red flowers is crossed with a plant with white flowers, what proportion of pla