Mastering Bio CH9 Questions and Answers| Already Passed Latest Update Graded A+

Mastering Bio CH9 Questions and Answers| Already Passed Latest Update Graded A+ In pea plants, the yellow seed allele (Y) is dominant over the green seed allele (y). What is the phenotypic ratio of yellow seeds to green seeds in the F2 generation resulting from a cross between two true-breeding parents, one with YY and one with yy? 3:1 Huntington's disease (HD) is a dominant genetic disorder with an onset in the late 30s, when many people have already started their families. What is the probability that a child born to a man with the HD allele (H) and a woman without this allele (h) will have Huntington's disease? Will the children who do not develop the disease be carriers of the HD allele? 50%: no The human X chromosome has about ______ genes. The Y chromosome has about ____ genes. The fruit fly has ____ chromosomes. 1,110: 78: 8 Some insects, such as grasshoppers and roaches, have a sex determination system called "X-O." What are the characteristics of males and females in this system? Females are XX: males are XO and half of their sperm lack a sex chromosome According to one hypothesis, the high prevalence of the sickle-cell allele in some people of African descent has a selective advantage. How does this work? The malarial parasite triggers sickling in red blood cells, causing the body's defense system to destroy both the cells and the parasite. An individual is heterozygous for a particular gene. Which of the following is true of this individual? Different alleles of the gene are present at the same locus on homologous chromosomes.