Deck 4: Heredity and Evolution

Question 1

Which is NOT true about random assortment?

A)There is a chance distribution of chromosomes to daughter cells.
B)It is an important source of genetic variation.
C)It produces new alleles.
D)It happens during meiosis.
E)It is important like recombination.

Answer 1

It produces new alleles.

Question 2

A trait is NOT expressed in heterozygotes, it is said to be

A)dominant.
B)codominant.
C)recessive.
D)homozygous dominant.
E)segregated.

Answer 2

recessive.

Question 3

In Mendel's experiments, the tall parental (P)plants

A)were heterozygous for the allele for tallness.
B)were heterozygous at the locus-controlling height.
C)could NOT be crossed with short plants.
D)were homozygous for the allele for shortness.
E)were homozygous for the allele for tallness.

Answer 3

were homozygous for the allele for tallness.

Question 4

Gregor Mendel

A)developed theories of evolutionary change.
B)discovered the structure of the DNA molecule.
C)studied characteristics that are influenced by several genetic loci.
D)discovered the fundamental principles of how traits are inherited.
E)developed the theory of inheritance of acquired characteristics.

Question 5

Which of the following is NOT inherited in a Mendelian fashion?

A)ABO blood type
B)Marfan syndrome
C)Achondroplasia
D)Phenylketonuria
E)Skin color

Question 6

The ABO blood type system consists of ______ alleles.

A)6
B)4
C)3
D)2
E)5

Question 7

Two people (both heterozygotes)are able to taste a chemical substance called PTC. The ability to taste PTC is caused by a dominant allele (T). The inability to taste PTC is caused by a recessive allele (t). What proportion of their offspring would be expected to be heterozygous?

A)3/4
B)1/2
C)All
D)1/4
E)2/3

Question 8

Two people (both heterozygotes)are able to taste a chemical substance called PTC. The ability to taste PTC is caused by a dominant allele (T). The inability to taste PTC is caused by a recessive allele (t). What proportion of their children would be expected to have the ability to taste PTC?

A)3/4
B)1/2
C)All
D)1/4
E)2/3

Question 9

The fact that both green and yellow peas were produced by tall pea plants in predictable frequencies  led Mendel to propose the

A)principle of segregation.
B)principle of independent assortment.
C)concept of dominance.
D)concept of codominance.
E)blending theory of inheritance.

Question 10

Two people (both heterozygotes)are able to taste a chemical substance called PTC. The ability to taste PTC is caused by a dominant allele (T). The inability to taste PTC is caused by a recessive allele (t). What proportion of their children would be expected to have the tt genotype?

A)3/4
B)1/2
C)All
D)1/4
E)2/3

Question 11

The observed physical manifestation of genes is the

A)genotype.
B)phenotype.
C)phenotypic ratio.
D)genotypic ratio.
E)independent assortment.

Question 12

An individual's actual genetic makeup is called the

A)phenotype.
B)homozygosity.
C)recessiveness.
D)phenotypic ratio.
E)genotype.

Question 13

In Mendel's experiments, the ratio of tall to short plants in the F₂ generation was

A)15 to 1.
B)3 to 1.
C)1 to 1.
D)4 to 1.
E)5 to 1.

Question 14

Gregor Mendel

A)published his results and won the Nobel Prize for his discoveries.
B)was trained as a geneticist.
C)died before the importance of his research was recognized.
D)was a professor at the University of Vienna.
E)never published his work.

Question 15

When Mendel crossed true-breeding tall and short parental plants,

A)all the offspring were tall.
B)half the offspring were tall, the other half were short.
C)all the offspring were short.
D)the offspring were intermediate in height relative to the two parent plants.
E)about 90 percent were tall, but the rest were short.

Question 16

Two people (both heterozygotes)are able to taste a chemical substance called PTC. The ability to taste PTC is caused by a dominant allele (T). The inability to taste PTC is caused by a recessive allele (t). What proportion of their children would be expected NOT to be able to taste PTC?

A)3/4
B)All
C)1/4
D)2/3

Question 17

When Mendel crossed plants and considered two traits simultaneously (e.g., height and seed color in peas), what proportion of the F₂ generation offspring expressed both recessive phenotypes?

A)9/16
B)8/16
C)12/16
D)3/16
E)1/16

Question 18

How do the basic principles of inheritance, identified by Mendel in plants, differ from those in humans?

A)They are simpler.
B)Plants don't have alleles.
C)There are no differences because the basic principles are the same.
D)There are no Mendelian traits in humans.
E)The number of chromosomes is different; therefore, the genetic principles are different.

Question 19

A person who is homozygous recessive at a locus has

A)two copies of the recessive allele.
B)two copies of the dominant allele.
C)an autosomal trisomy.
D)a recessive allele on the X chromosome only.
E)a recessive allele on the Y chromosome only.

Question 20

Dominant alleles

A)usually cause the underproduction of an enzyme.
B)always produce the most desirable phenotype.
C)can mask the expression of other alleles at the same locus.
D)are always the most common allele in a population.
E)were discovered by Charles Darwin.

Question 21

Polygenic traits

A)are discrete.
B)have a continuous range of expression.
C)are controlled by only one genetic locus.
D)include the ABO blood type system and cystic fibrosis.
E)are also called Mendelian traits.

Question 22

Sex-linked traits

A)have their loci on all chromosomes.
B)are expressed more often in females than in males.
C)are expressed in females in the same fashion as autosomal traits.
D)are carried mainly on the Y chromosome.
E)includes albinism.

Question 23

Which of the following is NOT a polygenic trait?

A)Stature
B)Skin color
C)Eye color
D)ABO blood type
E)Hair color

Question 24

A person with blood type B is heterozygous. What is that person's genotype?

A)BB
B)OO
C)BO
D)AB
E)none of these

Question 25

What produces new alleles at a locus?

A)Natural selection
B)Recombination
C)Mutation
D)Migration
E)Genetic drift

Question 26

When a person possesses two different alleles at the same locus, and both alleles are expressed in the phenotype, this is called

A)recessiveness.
B)codominance.
C)dominance.
D)homozygosity.
E)X-linkage.

Question 27

Which gene accounts for 74 percent of the variation in human eye color?

A)MC1R
B)OCA2
C)DELTA23
D)FOXP2
E)HOX

Question 28

Mendelian traits

A)are governed by several genetic loci.
B)are more likely to have identifiable loci than polygenic traits.
C)have continuous distributions.
D)can be described by statistics such as the average and standard deviation.
E)have phenotypic expressions that are often the result of genetic and environmental interactions.

Question 29

Which statement concerning polygenic traits is FALSE?

A)They are governed by more than one genetic locus.
B)Their expression is often influenced by genetic/environmental interactions.
C)They account for most observable phenotypic variation in humans.
D)They are not affected by environmental factors.
E)They are continuous.

Question 30

Evolution can be most succinctly defined as

A)the appearance of new species.
B)the change from one species to another in one generation.
C)a change in allele frequencies from one generation to the next.
D)any type of genetic mutation.
E)genetic drift.

Question 31

In order for a mutation to be passed on to an offspring, the mutation must

A)occur in a gamete.
B)be beneficial.
C)occur in a somatic cell.
D)result in additional chromosomes.
E)be a point mutation only.

Question 32

According to Modern Synthesis, evolution can be defined as a two-stage process that includes

A)genetic drift followed by migration.
B)natural selection followed by migration.
C)recombination followed by mutation.
D)variation followed by natural selection.
E)mutation and gene drift.

Question 33

A man who has type A blood has the AA genotype. His wife, with type B blood, has the BO genotype. Which of the following blood types is/are NOT possible for their children?

A)Type O
B)Type AB
C)Type A
D)Type AO
E)A codominant type

Question 34

Mendelian traits

A)are governed by more than one genetic locus.
B)occur only in some people.
C)are always dominant.
D)are discrete or discontinuous.
E)are always recessive.

Question 35

How many ABO phenotypes are there?

A)4
B)2
C)3
D)6
E)1

Question 36

In a hypothetical situation, B is the allele that causes brachydactyly. If a man who has normal fingers (bb)and a woman with brachydactyly (Bb)have children, what proportion of these children would you expect to have normal fingers? (Hint: Use a Punnett square.)

A)1/16
B)1/8
C)1/4
D)3/4
E)1/2

Question 37

At a hypothetical locus, a man's genotype is Aa. What proportion of his gametes would be expected to receive the A allele?

A)1/3
B)1/2
C)3/4
D)1/4
E)1/8

Question 38

Type AB blood is an example of

A)codominance.
B)blending.
C)recessiveness.
D)dominance.
E)polygenic inheritance.

Question 39

Short-term effects on inherited traits are sometimes called

A)macroevolution.
B)plieotropy.
C)microevolution.
D)speciation.
E)natural selection.

Question 40

Which of the following types of traits are governed by more than one genetic locus?

A)Polygenic
B)Dominant
C)Mendelian
D)Recessive
E)Pleiotropic

Question 41

Polygenic traits account for few, if any, of the readily observable phenotypic variation seen in humans.

Question 42

The only source(s)of new genetic variation in any population is/are

A)mutations.
B)genetic drift.
C)founder effect.
D)migration.
E)natural selection.

Question 43

The majority of sex-linked traits have loci on the X chromosome.

Question 44

Gene flow is defined as the

A)production of new alleles.
B)production of new genetic material.
C)chance loss of alleles in a population.
D)exchange of genes between populations.
E)differential reproductive success of individuals.

Question 45

Many human genetic result from harmful alleles inherited in a Mendelian manner.

Question 46

Achondroplasia is an example of an autosomal recessive trait.

Question 47

Dominance and recessiveness are all-or-nothing situations because the recessive allele has NO phenotypic effects in heterozygotes.

Question 48

Founder effect refers to a type of genetic drift in which allele frequencies are changed in small populations that are taken from larger populations or are left over from the latter.

Question 49

Researchers have identified six different modes of Mendelian inheritance.

Question 50

All variation in mtDNA is caused by mutation.

Question 51

Mendelian traits are more likely to be influenced by environmental factors.

Question 52

The Hb^S allele increased in frequency in West African populations due to

A)sickle-cell anemia.
B)genetic drift.
C)migration.
D)increased mutation rates.
E)natural selection.

Question 53

Recessive conditions are usually associated with the lack of production of an enzyme.

Question 54

Mendel worked with animal populations to formulate his principles of inheritance.

Question 55

Mendel's first principle of inheritance is independent assortment.

Question 56

Which of the below is FALSE regarding the relationship between malaria and the Hb^S allele?

A)There is no geographic correlation between the distribution of the Hb^S allele and malaria.
B)Heterozygotes have greater resistance to malaria than homozygous individuals.
C)The malarial parasite does not reproduce very well in the red blood cells of heterozygotes.
D)Malaria is caused by the Plasmodium parasite.
E)The Hb^S mutation probably occurs occasionally in all human populations.

Question 57

Allele frequencies are indicators of the genetic makeup of a population, the members of which share a common gene pool.

Question 58

Genetic drift is a result of

A)migrations.
B)an increase in population.
C)genetic diseases.
D)mutations.
E)a small population.

Question 59

Melanin production is a polygenic trait that is influenced by the interactions between several different loci.

Question 60

X-linked traits affect males and females in equal frequencies.

Question 61

Discuss the differences between Mendelian and polygenic modes of inheritance. Provide an example of a Mendelian and a polygenic trait.

Question 62

Explain the role of mutation to evolution, and then using the Hb^S allele to illustrate, describe why fitness levels are a function of the environment.

Question 63

Explain polygenic inheritance, and give examples of polygenic trains in humans.

Question 64

Explain why a woman with type O blood and a man with type A blood could potentially have children with either type A or O blood.

Question 65

What is the effect of genetic bottlenecks on human and nonhuman species?

Question 66

What are the typical Mendelian phenotypic and genotypic ratios in the F₂ generation for a cross of purebred tall and short plants?  Why are these ratios typical?

Question 67

Explain the genetic importance of mitochondrial inheritance.

Question 68

Explain the importance of the discoveries of Gregor Mendel to genetics and include an explanation of each of his principles.

Question 69

Compare and contrast polygenic and Mendelian traits.

Question 70

Describe and explain the factors that produce and redistribute variation.

Question 71

Discuss Modern Synthesis and its importance in bringing together natural selection and mutation as joint forces in biological evolution.

Question 72

Explain the concepts of dominance, codominance, and recessiveness as used in modern genetics.

Question 73

Describe the role of natural selection as directional and its relation to variation. Explain the example of Hb² and malaria.

Question 74

Describe some environmental factors that can influence genotypes.

Question 75

Explain random assortment.

Question 76

Explain how two parents who do NOT express a particular trait in their phenotype can nevertheless produce children who express the trait. Give an example of a specific trait or disease where this could occur.

Question 77

Explain the importance of mutation as a factor that produces variation and its importance to the evolutionary process.

Question 78

Explain Mendel's principle of segregation.

Question 79

List two evolutionary factors and their level of organization in the evolutionary process.