SOLVED

41. If the gene for blue eyes is recessive, and if John’s mother and father both have blue eyes, we know that John: a. will be homozygous on the eye color trait b. will be heterozygous on the eye color trait c. will have a 50% chance of having blue eyes d. will have a 25% chance of having blue eyes 4 Suppose that Shelly’s mother has brown eyes and her father has blue eyes. Shelly has brown eyes. In this example we would ______ Shelly’s phenotype for eye color and would _________ Shelly’s genotype for eye color. a. know; not know b. not know; know c. know; know d. not know; not know 43. Suppose that hair color is a single-gene trait and that dark hair is dominant and blonde hair is recessive. Also, suppose that Terry’s mother has dark hair and his father has blonde hair. If Terry has blonde hair, we would ______ Terry’s phenotype for hair color and would ________ Terry’s genotype for hair color. a. know; not know b. not know; know c. know; know d. not know; not know 44. Suppose that eye color is a single gene trait and that brown eyes is a dominant allele and blue eyes is a recessive allele. If Mark has brown eyes, we would know: a. that Mark is heterozygous for the eye color trait b. that Mark is homozygous for the eye color trait c. Mark’s genotype d. Mark’s phenotype 45. Assume that eye color is a single gene trait and that brown eyes is a dominant allele and blue eyes is a recessive allele. If Harry’s mother and father both have brown eyes and are both heterozygous on this trait, what is the probably that he will have brown eyes, too? a. 100% b. 75% c. 50% c. 25% 46. A mother and a father have four children (biological not adopted). All four children have blue eyes. Assuming that brown eyes is a dominant trait and blue eyes is a recessive trait, which of the following statements must be true? a. The parents may have brown or blue eyes, but both must have at least one allele for blue eyes. b. The parents may have brown or blue eyes, but both must have at least one allele for brown eyes. c. At least one of the parents must have blue eyes. d. Both of the parents must have blue eyes. 47. The term “polygenic inheritance” refers to which of the following? a. a trait that is determined by a single gene pair b. the idea that half of our genes come from each of our parents c. a trait that is present in the individual’s phenotype d. a trait caused by an interaction of several genes or gene pairs 48. Dr. Ramley states that intelligence is determined by the action of hundreds of different genes. She has just defined intelligence as a _________ trait. a. dominant b. recessive c. polygenic d. heterozygous 49. Color blindness is a sex-linked trait. As such, if a child is color blind, we can be assured that the child’s genotype includes: a. a recessive gene on the X chromosome inherited from his mother b. a dominant gene on the X chromosome inherited from his mother c. a recessive gene on the Y chromosome inherited from his father d. a dominant gene on the X chromosome inherited from his father 50. Sickle-cell anemia is a genetic disorder that is best considered an example of: a. dominance b. incomplete dominance c. recessive alleles d. codominance