ch. 14

Part complete Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. Also, a second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all. The relationship between genes S and N is an example of which of the following inheritance patterns? -incomplete dominance -pleiotropy -codominance -epistasis

-epistasis

Which of the following best describes how an individual with genotype AaBbCCDdEE can make haploid gametes with different genotypes? -mutations during meiosis form new alleles that are incorporated into the gametes -the inheritance of a particular copy of one chromosome does not affect the inheritance of a different chromosome -crossing over during prophase I leads to increased genetic diversity -dominant alleles tend to be inherited together

-the inheritance of a particular copy of one chromosome does not affect the inheritance of a different chromosome

Part complete In a certain species of diploid fish a single gene controls skin color. Researchers have found four different alleles of this gene within the fish population. How many different gamete genotypes are possible in an individual of this species? -4 -8 -16 -2

2

In some parts of Africa, the frequency of individuals who are heterozygous for the sickle-cell anemia allele is higher than the frequency in North America, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? -Mendel's law of segregation - Punnett square's modelling inheritance -Mendel's law of independent assortment -Darwin's theory of natural selection

Darwin's theory of natural selection

Which of the following describes why Mendel continued some of his experiments into the F2 or F3 generation? -Determining whether a dominant trait would reappear required multiple dihybrid crosses. -Following multiple generations allowed him to determine whether a recessive trait would reappear. -Data from the F1 generation did not allow him to distinguish which alleles were segregating -Collecting data from more generations allowed him to obtain a larger number of offspring.

Following multiple generations allowed him to determine whether a recessive trait would reappear.

Which of the following statements about the law of segregation is correct? -It describes the inheritance of different chromosomes relative to one another. -It describes situations where either genotype or environment affect phenotype, but not both. -It describes the inheritance of different alleles relative to one another. -It explains how codominant alleles each affect the phenotype in separate ways.

It describes the inheritance of different chromosomes relative to one another.

Which of the following statements best describes the addition rule of probability? -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 of two independent events will occur. -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.

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? -Both of the parents are homozygous at that locus -Neither of the parental alleles is expressed in the offspring -Both of the parents have dominant alleles. -Neither of the parental alleles is dominant over the other. Submit

Neither of the parental alleles is dominant over the other.

Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately break down the amino acid phenylalanine. This amino acid is not naturally produced by humans. Which of the following treatments would be most effective for people with PKU? -Feed the individual an excess of the missing product. -Feed the individual the missing enzymes in a regular cycle, such as twice per week. -Regulate the individual's diet to severely limit the uptake of phenylalanine. -Feed the individual the substrate that can be metabolized into phenylalanine.

Regulate the individual's diet to severely limit the uptake of phenylalanine.

Which of the following phenotypes is an example of polygenic inheritance? -pink flowers in snapdragons -the ABO blood group in humans -skin pigmentation in humans -white and purple flower color in peas

skin pigmentation in humans