Ch. 9 Bio 101

Which one of the following statements is not true? a. is more difficult to trace patterns of inheritance in purebred dogs . b. Dogs of different breeds have different temperaments. c. A human's behavioral characteristics are influenced by its genetics and its environment. d. About 60% of the genetic disorders in dogs are similar to human genetic diseases. e. A dog's behavioral characteristics are influenced by its genetics and its environment.

... not D

Both amniocentesis and chorionic villus sampling allow for __________ and __________ of the fetus so that it can be tested for abnormalities. a. karyotyping . . . biochemical testing b. direct observation . . . biochemical testing c. imaging . . . biochemical testing d. imaging . . . karyotyping e. sexing . . . imaging

A

Genes located close together on the same chromosomes are referred to as __________ genes and generally __________. a. linked . . . do not sort independently during meiosis b. homologous . . . are inherited together c. codependent . . . do not sort independently during meiosis d. linked . . . sort independently during meiosis e. associated . . . sort independently during meiosis

A

Imagine that beak color in a finch species is controlled by a single gene. You mate a finch homozygous for orange (pigmented) beak with a finch homozygous for ivory (unpigmented) beak and get numerous offspring, all of which have a pale, ivory-orange beak. This pattern of color expression is most likely to be an example of a. incomplete dominance. b. pleiotropy. c. polygenic inheritance. d. crossing over. e. codominance.

A

Recessive sex-linked human conditions include which of the following? a. red-green color blindness, muscular dystrophy, and hemophilia b. albinism c. hemophilia d. muscular dystrophy e. red-green color blindness

A

Which of the following kinds of data could be used to map the relative position of three genes on a chromosome? a. the frequencies with which the corresponding traits occur together in offspring b. the frequencies with which the genes are inherited from the mother and from the father c. the frequencies with which the genes are heterozygous d. the frequencies of mutations in the genes e. the frequencies with which the genes exhibit incomplete dominance over each other

A

Which of the following terms refers to the situation where a single phenotypic characteristic is determined by the additive effects of two or more genes? a. polygenic inheritance b. blending inheritance c. incomplete dominance d. codominance e. pleiotropy

A

Which one of the following is an example of incomplete dominance in humans? a. hypercholesterolemia b. sickle-cell disease c. None of the choices are correct. d. ABO blood groups e. pink coloration in snapdragons

A

Alleles of a gene are found at __________ chromosomes. a. the same locus on heterologous b. the same locus on homologous c. the same locus on homologous mitochondrial d. different loci on heterologous e. different loci on homologous

B

An animal species in which an individual produces both eggs and sperm is called a. dioecious. b. hermaphroditic. c. monoecious. d. polyploid. e. pleiotropic.

B

Crossing over __________ genes into assortments of __________ not found in the parents. a. recombines unlinked . . . genes b. recombines linked . . . alleles c. combines unlinked . . . alleles d. recombines unlinked . . . chromosomes e. combines linked . . . genes

B

Using a six-sided die, what is the probability of rolling either a 5 or a 6? a. 1/6 b. 1/6 + 1/6 = 1/3 c. 1/6 + 1/6 = 1/12 d. 1/6 x 1/6 = 1/3 e. 1/6 x 1/6 = 1/36

B

Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as a. hybrids. b. true-breeding. c. monohybrid crosses. d. the F2 generation. e. independent crosses.

B

A plant species in which individual plants produce both sperm and eggs is called a. dioecious. b. pleiotropic. c. monoecious. d. hermaphroditic. e. polyploid.

C

Any gene located on a sex chromosome a. will exhibit pleiotropy. b. is called a dominant allele. c. is called a sex-linked gene. d. will exhibit codominance. e. is called a recessive gene.

C

How is sex determined in most ants and bees? Sex is determined by the a. size of the sex chromosome. b. Z-W system. c. number of chromosome sets. d. X-O system. e. X-Y system.

C

How many sex chromosomes are in a human gamete? a. four b. two c. one d. three e. five

C

In a cross of a purple-flowered, short-stemmed plant with a yellow-flowered, long-stemmed plant, the expected phenotypic ratio is 1 purple-short:1 purple-long:1 yellow-short:1 yellow-long. When you do the actual cross you observe a 5 purple-short:1 purple-long:1 yellow-short:5 yellow-long phenotypic ratio. Which of the following explains these results? a. The genes are linked and the relationship between the alleles involved in determining the phenotype is incomplete dominance. b. The purple-long and yellow-short individuals are recombinants. c. The genes are linked. d. The gene determining the phenotype has pleiotropic effects. e. The relationship between the alleles involved in determining the phenotype is incomplete dominance.

C

The chromosome theory of inheritance states that a. chromosomes that exhibit mutations are the source of genetic variation. b. the behavior of chromosomes during mitosis accounts for inheritance patterns. c. the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance. d. humans have 46 chromosomes. e. None of the choices are correct.

C

What is a testcross? a. a mating between an individual of unknown genotype and an individual heterozygous for the trait of interest b. a mating between two individuals heterozygous for the trait of interest c. None of the choices are correct. d. a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest e. a mating between an individual of unknown genotype and an individual homozygous dominant for the trait of interest

C

What is the normal complement of sex chromosomes in a human male? a. two X chromosomes and one Y chromosome b. two Y chromosomes c. one X chromosome and one Y chromosome d. two X chromosomes e. one Y chromosome

C

Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes? a. DD and dd b. None of the choices are correct. c. DD and DD d. Dd and Dd e. dd and dd

D

Many genetic disorders of humans are caused by a. None of the choices are correct. b. a mutation that occurs in the egg, sperm, or zygote that gives rise to the affected individual. c. drinking during pregnancy. d. recessive alleles. e. dominant alleles.

D

The expression of both alleles for a trait in a heterozygous individual is a. pleiotropy. b. polygenic inheritance. c. incomplete dominance. d. codominance. e. blending inheritance.

D

The vast majority of people afflicted with recessive disorders are born to parents who were a. None of the choices are correct. b. both affected by the disease. c. subjected to some environmental toxin that caused the disease in their children. d. not affected at all by the disease. e. slightly affected by the disease, showing some but not all of the symptoms.

D

Which one of the following is not true? a. Sickle-cell disease is common in tropical Africa. b. About one in 10 African Americans is a carrier of sickle-cell disease. c. Persons who are heterozygous for sickle-cell disease are also resistant to malaria. d. White blood cells are sickle shaped in sickle-cell disease. e. All of the symptoms of sickle-cell disease result from the actions of just one allele.

D

Which one of the following is not true? a. The expressed physical traits of an organism are called its phenotype. b. An organism with two different alleles for a single trait is said to be heterozygous. c. The genetic makeup of an organism constitutes its genotype. d. An allele that is fully expressed is referred to as recessive. e. Alleles are alternate forms of a gene.

D

A carrier of a genetic disorder who does not show symptoms is most likely to be __________ to transmit it to offspring. a. homozygous for the trait and unable b. heterozygous for the trait and unable c. homozygous for the trait and able d. None of the choices are correct. e. heterozygous for the trait and able

E

Assuming that the probability of having a female child is 50% and the probability of having a male child is also 50%, what is the probability that a couple's first-born child is female and second-born child is male? a. 75% b. 50% c. None of the choices are correct. d. 100% e. 25%

E

Mendel's principle of independent assortment states that a. None of the choices are correct. b. chromosomes sort independently of each other during mitosis and meiosis. c. genes sort independently of each other in animals but not in plants. d. independent sorting of genes produces polyploid plants under some circumstances. e. each pair of alleles segregates independently during gamete formation.

E

What is meant by the statement that "male bees are fatherless"? a. Male bees don't play a role in the rearing of bee young. b. Male bees develop from fertilized eggs. c. The queen bee's mate dies before the male eggs hatch. d. Male bees are produced by budding. e. Male bees develop from unfertilized eggs.

E

Which of the following best explains why dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders? a. Many lethal recessive alleles cause enhanced disease resistance when they are present in the heterozygous state, and carriers of these alleles have more children, on average, than other people. b. Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles. c. The presence of a lethal dominant allele causes sterility. d. Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause death of the embryo. e. Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce.

E

Which one of the following is not true? a. Heterozygotes for hypercholesterolemia have blood cholesterols about twice normal. b. The four blood types result from various combinations of the three different ABO alleles. c. The impact of a single gene on more than one characteristic is called pleiotropy. d. ABO blood groups can provide evidence of paternity. e. Incomplete dominance supports the blending hypothesis.

E

Which one of the following is not true? a. The complication rate for chorionic villus sampling is about 2% and for amniocentesis is about 1%. b. Results from chorionic villus sampling come faster than from amniocentesis. c. Ultrasound imaging has no known risk. d. Chorionic villus sampling and amniocentesis are usually reserved for pregnancies with higher than usual risks of complications. e. Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis.

E

Which one of the following statements best represents the theory of pangenesis developed by Hippocrates? a. Particles called pangenes originating in each part of an organism's body collect in the sperm and eggs and are passed on to the next generation. b. Offspring inherit the traits of either the mother or the father but not both. c. Pregnancy is a spontaneous event, and the characteristics of the offspring are determined by the gods. d. None of the choices are correct. e. Fertilization of plants is dependent on an animal.

a. Particles called pangenes originating in each part of an organism's body collect in the sperm and eggs and are passed on to the next generation.

Which one of the following statements is not true? a. Aristotle suggested that inheritance is the potential to produce body features. b. The blending hypothesis suggested that all of the traits of the offspring come from either the mother or the father. c. Pangenesis is incorrect in part because changes in somatic cells do not influence eggs or sperm. d. Pangenesis is incorrect in part because reproductive cells are not composed of particles from somatic cells. e. The blending hypothesis does not explain how traits that disappear in one generation can reappear in later generations.

b. The blending hypothesis suggested that all of the traits of the offspring come from either the mother or the father.

A monohybrid cross is a. the second generation of a self-fertilized plant. b. a breeding experiment in which the parental varieties have only one trait in common. c. a breeding experiment in which the parental varieties differ in only one trait. d. a triploid plant that results from breeding two very different plants. e. None of the choices are correct.

c. a breeding experiment in which the parental varieties differ in only one trait.

Why are sex-linked conditions more common in men than in women? a. None of the choices are correct. b. Men acquire two copies of the defective gene during fertilization. c. Women simply do not develop the disease regardless of their genetic composition. d. Men need inherit only one copy of the recessive allele for the condition to be fully expressed. e. The sex chromosomes are more active in men than in women.

d. Men need inherit only one copy of the recessive allele for the condition to be fully expressed.

Which one of the following is not true? a. The offspring of two different varieties are called hybrids. b. The cross-fertilization or hybridization is also called a cross. c. The parental plants of a cross are the P generation. d. The hybrid offspring of an F1 cross are the F2 generation. e. The hybrid offspring of a cross are the P1 generation.

e. The hybrid offspring of a cross are the P1 generation.

Research since Mendel's time has established that the principle of the segregation of genes during gamete formation a. applies to all asexually reproducing organisms. b. applies only to unicellular organisms. c. applies to all forms of life. d. is invalid. e. applies to all sexually reproducing organisms

e. applies to all sexually reproducing organisms