Chapter 14 biology

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of crosses BBSs ×BBSs will be expected to have black fur and long tails? a)3/8 b)1/16 c)9/16 d)1/2

1/2

If the parent or offspring genotypes or phenotypes are known, the pattern of inheritance can be predicted. Two organisms, with genotypes BbDD and BBDd, are mated. Assuming independent assortment of the two loci, which of the following genotypic ratios in offspring would occur? 1 BBDD;1 BbDD;1BBDd;1BbDd 9BBDD: 3BbDD: 3BBDd: 1bbdd 1 BBDD; 1bbdd 1BBDD;2BbDd:1bbdd

1BBDD; 1BbDD; 1BBDd;1BbDd

Which of the following statements correctly describes the terms monophybrud and dihybrid cross? A dihybrid cross involves organisms that are heterozygous for two characters being studied, and a mono hybrid cross involves organisms that are heterozygous for only only character being studied . A mono hybrid cross results in a 9:3:3:1 ratio, whereas a dihybrid cross gives a 3:1 ratio A mono hybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations A mono hybrid cross involves a single parent, whereas a dihybrid cross involves two parents

A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a Monohybrid cross involves organisms that are heterozygous for only one character being studied

In human blood types, Rh positive is a trait that shows simple dominance over Rh negative. The Rh phenotype is recorded by stating "positive" or "negative" after the individuals ABO blood type. A woman who has the blood type A positive has a daughter who is type O positive and a son who is type B negative. Which of the following phenotypes is possible for the father? B positive O negative A negative AB negative

B positive

Which of the following calculations requires the use of addition rule of probability? Calculating the probability that a cross between an ahh and an h will result in four offspring that are each homozygous recessive Calculating the probability of green plants from the cross AaGgxAaGg, where G is the symbol for black and A is the symbol for tall Calculating the probability h that parents who are heterozygous for both cystic fibrosis and polydactyl genes will have a child with both cystic fibrosis and polydactyl Calculating the probability of a child having either sickle cell anemia or cystic fibrosis if parents are each heterozygous for both

Calculating the probability of a child having either sickle cell anemia or Cystic fibrosis if parents are each heterozygous for both

Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The flower color trait in radishes is an example of which of the following inheritance patterns? a)incomplete dominance b)sex linkage c)codominance d)a múltiple allelic system

Incomplete dominance

Which of the following statements about the law of independent assortment is correct? a)it is the consequence of having two copies of each chromosome in somatic cells and one copy in gametes b) it describes the inheritance of different genes relative to one another c) it is the reason that dominant alleles are visible in the organisms phenotype d) it describes the inheritance of different alleles relative to one another

It describes the inheritance of different genes relative to one another

Which of the following statements best describes the addition rule of probability? It is the probability that a trait requires two or more generations to be seen It is the probability that either one of two independent events will occur. It is the probability of producing two or more heterozygous offspring. It is the probability that two or more independent events will occur simultaneously

It is the probability that either one or two independent events will occur

Which of the following statements correctly explains the observation that parents with two different phenotypes produced offspring with a phenotype that is a blend of the two parental varieties? a)both of the parents are homozygous at the locus b)neither of the parental alleles is expressed in the offspring c)both of the parents have dominant alleles d)neither of the parental alleles is dominant over the other

Neither of the parental alleles is dominant over the other

Why did all of the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties? a) no genes interacted to produce a new unique phenotype b) one allele was dominant c) the traits blended together during fertilization d) each allele affected phenotypic expression

One allele was dominant

Which of the following phenotypes is an example of polygenic inheritance? a) the ABO blood group in humans b)white and purple flower color in peas c)skin pigmentation in humans d)pink flowers in snap dragons

Skin pigmentation in humans

Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether or not cactuses have spines. Homozygous recessive nn cactuses have no spines at all. Which of the following would explain why crossing a true breeding cactus with a dull spiked cactus could result in both sharp and dull spiked offspring? a)Gene-N genotype is polygenic b) the spineless cactus was heterozygous at the S locus c)sharp-spines cacti are more successful in environments with predators d)Gene S genotype is pleiotropic

The spineless cactus was heterozygous at the S locus

Which of the following statements correctly describes how Mendel explained why traits disappeared in the F1 generation and then reappeared in the F2 generations? Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in F1 New mutations were frequently generated in the cross that generated F2 offspring, causing traits that had been lost in the F1 to reappear in the F2 Members of the F1 generation had only one allele for each trait, but members of F2 had two alleles for each trait The mechanisms control the appearance of traits in the F1 and the F2 plants were different

Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in F1

A brown dog crossed with a yellow dog produced 12 brown offspring. A second brown individual was obtained. When the yellow dog was crossed with this animal, six brown and six yellow offspring were born. Which of the following best explains the results of the second cross? a) yellow and brown are codominant b)yellow is a recessive trait;brown is codominant c) yellow is a dominant traut;brown is incompletely dominant d)yellow is a recessive trait; brown is a dominant trait

Yellow is a recessive trait;brown is a dominant trait

Feather color in budgies is determined by two different genes, Y and B, one for pigment on the outside and one for the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. Two blue budgies were crossed. Over the years, they produce 22 offspring, five of which were white. What are the most likely genotypes for the two blue budgies? a)yyBb and yybb b)yyBB and yyBb c)yyBB and yyBB d)yyBb and yyBb

yyBb and yyBb

Feather color in budgies is determined by two different genes, Y and B, one for pigment on the outside and one for the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. A blue budgie is crossed with a white budgie. Which of the following results is NOT possible? blue offspring only White offspring only Green offspring only Blue and white offspring

Blue offspring only