Bsc1005 BIO Chapter 7

Bsc1005 BIO Chapter 7 Put the potential offspring genotypes in order from highest expected frequency to lowest expected frequency for a cross in which both parents have the RrTt genotype. a. RrTt rrTt RRtt b. RrTt RRtt rrTt c. rrTt RRtt RrTt - Answer- a Which of the following describe conclusions drawn by Gregor Mendel? a. Dominant traits are capable of masking the phenotype of recessive traits. b. An organism's phenotype is determined by genes located on chromosomes. c. The alleles responsible for a trait are separated and passed down to the following generation. d. Some traits are complex and controlled by many different genes. - Answer- a, c Two people of medium skin tone have five children, each with a different skin tone ranging from very pale to very dark. Most of the children's skin becomes a little bit darker after exposure to the sun. Judging from this information, skin tone is probably what? a. influenced by the environment b. a pleiotropic trait c. a Mendelian trait d. a polygenic trait - Answer- a, d In Labrador dogs, coat color is controlled by the genotypes of two genes. In one gene, the dominant allele, B, produces black fur, and the recessive allele, b, produces brown fur. However, if a second gene possesses two recessive alleles, ee, the dog produces yellow fur, regardless of the genotype of the first gene. If two dogs that are heterozygous for both genes, BbEe mated, what would be the frequency of the three phenotypes, black, brown, and yellow? - Answer- yellow: 4/16 black: 9/16 brown: 3/16 BIO cpt2,5 - Answer- starred Tess's sister is known to carry an allele for a single-gene recessive genetic disorder that is fatal in very early life. Tess's mother was tested for the allele and found not to carry it. What are the odds that Tess is a carrier for the allele? - Answer- Since the alleles that are passed on are random, Tess has a 1/2 (or 50%) chance of carrying the allele.