Deck 4: Evolution, Genetics, and Human Variation

Question 1

Natural selection cannot work without

A)a stable environment.
B)basic similarity in the target organisms.
C)constant gene frequencies.
D)variation.
E)homeostasis.

Answer 1

variation.

Question 2

__________ refers to an organism's evident biological characteristics.

A)Phoneme
B)Genotype
C)Biological circumscription
D)Phenotype
E)Hereditary inequality

Answer 2

Phenotype

Question 3

Rather than attempting to classify humans into racial categories, biologists and anthropologists are

A)denying the existence of any biological variation among humankind.
B)attempting to create new categories based only on blood type.
C)confident that earlier racial classifications are still valid.
D)trying to verify anthropometric data from the turn of the century.
E)seeking to explain why specific biological variations occur.

Answer 3

seeking to explain why specific biological variations occur.

Question 4

Independent assortment and recombination play a role in evolution by

A)limiting the amount of variation in a population.
B)increasing the frequencies of deleterious genes.
C)limiting the number of potential phenotypes.
D)creating genetic variability in a breeding population.
E)reducing the overall fitness of a breeding population.

Question 5

Gene flow and interbreeding act against

A)migration.
B)speciation.
C)natural selection.
D)mutations.
E)balanced polymorphisms.

Question 6

In evolutionary terms, natural selection is the process that favors the organism's ability to

A)displace natural predators from many different niches.
B)become as specialized as possible.
C)control the largest amount of resources in a particular niche.
D)survive and reproduce.
E)mature more rapidly than other organisms.

Question 7

Natural selection acts on

A)heterozygous individuals.
B)the phenotypes of organisms.
C)the genotypes of organisms.
D)DNA.
E)Mitochondrial DNA.

Question 8

Mendelian genetics studies

A)changes in gene frequencies in breeding populations.
B)the ways in which chromosomes transmit genes across generations.
C)how nuclear DNA transmits information to other parts of the cell.
D)evolution in pea plants.
E)phenotypic mutations.

Question 9

___________ states that explanations for past events should be sought in the long-term action of natural forces that are still observable.

A)Uniformitarianism
B)Creationism
C)Catastrophism
D)Recombination
E)Independent assortment

Question 10

Natural selection

A)is unique to flowering plants.
B)operates when there is competition for strategic resources.
C)is the driving principle behind creationism.
D)was discovered by Gregor Mendel.
E)operates only on single-celled animals because their genotypes are adaptable to environments.

Question 11

__________ is not part of Darwin's theory of evolution.

A)Catastrophism
B)Competition for resources
C)Variety in a population
D)Change in form over generations
E)Natural selection

Question 12

___________ created the first biological classification (taxonomy) of plants and animals.

A)Sir Charles Lyell
B)Charles Darwin
C)Gregor Mendel
D)Alfred Russel Wallace
E)Carolus Linnaeus

Question 13

The term gene flow refers to

A)the random loss of genes through sampling error.
B)the genetic mutations that occur during meiosis.
C)the movement of alleles from one chromosome to another.
D)the transmission of genetic material between populations of the same species.
E)a random pattern of chromosome mutations.

Question 14

The simple definition of evolution is

A)natural selection.
B)mutations in a breeding population.
C)descent with modification.
D)the process of achieving a perfect fit to the environment.
E)competition over strategic resources.

Question 15

Syphilis apparently originated in the Americas as a Disease that spread through

A)skin-to-skin contact.
B)sexual transmission.
C)airborne transmission (coughing and sneezing).
D)blood-to-blood contact.
E)contact with farm animals.

Question 16

The relationship between the alleles that determine our blood types is

A)dominant and recessive
B)dominant, recessive, and codominant
C)F₂ directional selection
D)cogenotypes
E)core combination

Question 17

The allele Hb^S that codes for the type of hemoglobin associated with sickle-cell anemia

A)is distributed evenly throughout all human populations.
B)less susceptible to malaria.
C)is always lethal when found in a human population.
D)has no effect on the viability of a population.
E)is never expressed in the phenotype when present in a homozygous state.

Question 18

___________ refers to all of the genetic material in a breeding population.

A)Genotype
B)Allele
C)Gene pool
D)Gene flow
E)Chromosome

Question 19

__________ is the process that produces sex cells.

A)Directional selection
B)Recombination
C)Mitosis
D)Independent assortment
E)Meiosis

Question 20

__________ is not one of the primary mechanisms of genetic evolution.

A)Gene flow
B)Natural selection
C)Independent assortment
D)Mutation
E)Genetic drift

Question 21

__________ plays a role in determining skin color.

A)The Hb^S allele
B)Ultraviolet radiation
C)Sickle-cell anemia
D)Lactose intolerance
E)Lactose tolerance

Question 22

The statement, __________, is not true.

A)"genetic drift can operate in any population, large or small"
B)"fixation due to genetic drift is more rapid in large populations"
C)"genetic drift is a mechanism of genetic evolution"
D)"it is a change in allele frequency that results from chance"
E)"alleles can be lost by chance rather than because of any disadvantages they confer"

Question 23

Discuss at least three characteristics of evolution that qualify it as a scientific theory.

Question 24

Explain why differences exist in skin pigmentation among human populations around the world.

Question 25

Identify and discuss the sources of genetic variety on which natural selection may operate.

Question 26

Some populations like the Polynesians, the San, or the people of northern India have phenotypes that do not fit neatly into "standard" racial categories, which suggests that

A)it is best to classify humans into a large number of racial categories.
B)phenotypical variation between human populations involves gradual shifts across different geographic zones.
C)these populations must have originated sometime before the major racial groups originated.
D)traditional concepts of race need to be reworked so that they are more exclusive.
E)there has been a lot of gene flow in the time since the origin of the three major human races.

Question 27

__________ describes the process that allows the selection of certain traits of one sex because of advantages they confer in winning mates.

A)Mitosis
B)Genotype
C)Directional selection
D)Sexual selection
E)Independent assortment

Question 28

Human populations living in temperate, northern climates generally have light skin color because it

A)helps to prevent rickets.
B)exists in a balanced polymorphism.
C)helps to prevent sickle-cell anemia.
D)helps to protect against skin cancer.
E)protects against hypervitaminosis

Question 29

Discuss the differences between creationism, catastrophism, uniformitarianism, and evolution.Explain how and why each view would define human variation and the fossil record.

Question 30

The theory of creationism argues that natural selection of the fittest individuals created all species that are present today.

Question 31

Discuss some of the problems underlying phenotype-based racial classifications.

Question 32

__________ are gradual genetic shifts are found among human population.

A)Mutations
B)Alleles
C)Clines
D)Genotypes
E)Balanced polymorphisms

Question 33

The example that the heterozygote Hb^S Hb^A, one sickle-cell allele and one normal one, was maintained in some populations as the fittest phenotype for a malarial environment demonstrates

A)mutation.
B)genetic drift.
C)phenotypical adaptation.
D)recombination.
E)balanced polymorphism.

Question 34

By __________ in Europe, the syphilis bacterium mutated into venereal syphilis, and it became a major killer during the Renaissance.

A)1252
B)1380
C)1402
D)1493
E)1628

Question 35

Discuss Charles Darwin's major contributions to the study of life forms.Discuss what was new about Darwin's views, and what others had previously proposed.

Question 36

Explain how the modern anthropological approach to the study of human biological diversity differs from racial classification,

Question 37

__________ causes neural tube defects.

A)An overproduction of vitamin D
B)An underproduction of vitamin D
C)A diet rich in fatty fishes
D)The Hb^S allele
E)The destruction of folate
Essay Questions

Question 38

Identify how population geneticists define evolution.Include a discussion of the major mechanisms of genetic evolution.

Question 39

The example of extended lactose tolerance in humans tell us that

A)it is entirely under genetic control, and researchers agree that the environment plays no role in its development.
B)it is one of many aspects of human biology governed by both genes and by phenotypical adaptation to environmental conditions.
C)the production of the enzyme lactase and the ability to tolerate milk remain the same among all human populations.
D)studies indicate that people cannot increase their lactose tolerance, thereby discounting the theory of phenotypical adaptation.
E)a simple genetic trait accounts for the ability to digest milk.

Question 40

Discuss what it means when a trait is adaptive or maladaptive depending on environmental conditions.Give at least one example.

Question 41

Genotype refers to expressed traits that are determined by genetic makeup.

Question 42

Directional selection reduces genetic variation by removing maladaptive traits from a gene pool.

Question 43

Higher amounts of melanin in the skin inhibit the body's ability to manufacture vitaminD.

Question 44

Mendelian genetics studies the ways in which gene frequencies vary in communities from generation to generation.

Question 45

Gene flow between populations tends to prevent speciation.

Question 46

Humans have a total of 46 alleles.

Question 47

Phenotypical adaptation is made possible by biological plasticity - the ability to change in response to the environments humans encounter as they grow.

Question 48

Uniformitarianism states that the natural forces at work today are more or less the same as those that operated in the past.

Question 49

Racial classifications do not accurately represent the wide diversity of biological traits present among human populations.

Question 50

One of Mendel's contributions to genetics was his discovery that traits are inherited as discrete units.

Question 51

Recessive traits are expressed only in homozygous individuals.

Question 52

The inheritance of acquired characteristics is central to Darwin's theory of evolution.

Question 53

Mutations introduce genetic variation into a gene pool.

Question 54

Random genetic drift is most common in large breeding populations.

Question 55

An overabundance of vitamin D in the body causes rickets.

Question 56

Natural selection operates directly on the genotype of an organism.

Question 57

Differential resistance to infectious diseases such as smallpox has influenced the distribution of the enzyme lactase.

Question 58

Microbes have been major selective agents for humans, particularly before the arrival of modern medicine.

Question 59

Genetic evolution involves changes in gene frequencies between generations within a given breeding population.

Question 60

Variety within a population is the only necessary condition for natural selection to operate.

Question 61

Folate aids in the production of sperm.

Question 62

UV radiation causes the destruction of folate.