BIOL 112 Exam 1

Question 1

The binomial system assigns to each organism a unique name that describes its ____

Answer 1

Genus and Species

Question 2

Which of the following conditions would allow gene frequencies to change by chance?

Answer 2

Small Population

Question 3

The three domains of life are

Answer 3

Bacteria, Archaea, Eukarya

Question 4

Which scientist proposed “Descent with modification”?

Answer 4

Charles Darwin

Question 5

In _____, the fitness of a phenotype depends on how much common it is in the population.

Answer 5

Frequency dependent selection

Question 6

Which of the following involves strengthening reproductive barriers so as to reduce the formation of unfit hybrids?

Answer 6

Stability

Question 7

Which of the things below describes a phylogenetic tree that is rooted?

Answer 7

A tree that has a common ancestor to all organisms on that tree at the base

Question 8

A defining characteristic of allopatric speciation is

Answer 8

Geographic Isolation

Question 9

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structures similarities are an example of ____

Answer 9

Homology

Question 10

In a phylogenetic tree, when two lineages stem from the same branch point, they are _____.

Answer 10

Sister taxa

Question 11

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that ____.

Answer 11

Island forms are descended from mainland forms

Question 12

Which among the following leads to sympatric speciation?

Answer 12

Polyploidy

Question 13

Which of the following mechanisms DOES NOT decrease genetic variance?

Answer 13

Diversifying Selection

Question 14

Genetic Variation _____.

Answer 14

Must be present in a population before natural selection can act upon the population

Question 15

The Linnaeus Classification system grouped organisms by ___.

Answer 15

Increasingly more specific groups

Question 16

When individuals of one sex compete directly for mates of the opposite sex, it is known as ___.

Answer 16

Intrasexual selection

Question 17

Which of the following is not an example of a prezygotic barrier?

Answer 17

Two species of insects produce infertile offspring

Question 18

WHich of the following statements describes a mechanical isolation prezygotic barrier?

Answer 18

Two snails have shells that spiral in different directions

Question 19

Which one of these processes describes bottleneck effect?

Answer 19

Sudden change in environments that alters gene frequency of a population

Question 20

Which of the following scientific terms is used to describe a pattern of speciation that happens rapidly followed by a long period of stability?

Answer 20

Punctuated

Question 21

Use the following tree to answer the question. Which tree depicts the same relationship?

A B C D-E. F-G.

Answer 21

G-F E-D. C B A

Question 22

In a Hardy-Weinberg popultion with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the frequency of individuals that are heterozygous for this allele?

Answer 22

a= .2
p= .8
2(.2)(.8)= .32

Question 23

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection?

1. Well adapted individuals leave more offspring than do poorly adapted individuals
2. A change occurs in the environment
3. Genetic frequencies within the population change
4. Poorly adapted individuals have decreased survivorship

Answer 23

2->4->1->3

Question 24

Arrange the following in order from most general to most specific
1. Natural Selection
2. Microevolution
3. Intrasexual Selection
4. Evolution
5. Sexual Selection

Answer 24

4, 2, 1, 5, 3

Question 25

Which of the following is the most predictable outcome of increased gene flow between two populations?

Answer 25

Decreased genetic difference between the two populations

Question 26

If natural selection favors an average phenotype, selecting against extreme variation, the population will undergo

Answer 26

Stabilizing Selection

Question 27

The best classification system is that which closely ___

Answer 27

Reflects evolutionary history

Question 28

Which of the following is the proper format of binomial nomenclature for the African Lion?

Answer 28

Panthera leo (italicized)

Question 29

Butterfly allele frequency

Answer 29

0.3

Question 30

Which of the following descriptions illustrates phenotype variation caused by environment?

Answer 30

Diet of caterpillars changes their morphology

Question 31

Rank the following in order from most general to most specific
1.gametic isolation
2.reproductive isolation mechanism
3.sperm-egg incompatibility in sea urchins
4.prezygotic isolation mechanism

Answer 31

2,4,1,3

Question 32

Which geologist proposed “gradualism”?

Answer 32

James Hutton

Question 33

Microevolutions occur when

Answer 33

change in allele frequencies in a population occur over generations

Question 34

The production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) is an example of

Answer 34

Reduced hybrid fertility

Question 35

Genetic Drift produces variation for evolution when ____

Answer 35

chance event causes allele frequencies to fluctuate unpredictably

Question 35

Two species of frogs belonging to the same genus occasionally mate, but the embryos stop developing after a day and die. These two frogs species separate by ___

Answer 35

Reduced hybrid viability

Question 35

Which of the follow describes this genetic grouping?

Answer 35

(D and E sister taxa, grouped with F connected but in different sister taxa) Paraphyletic

Question 36

Whenever diploid populations are in HArdy-Weiberg equilibrium at a particular locus, __

Answer 36

The allele frequency should not change from one generation to the next

Question 36

What are adaptations?

Answer 36

Inherited characteristics of organisms that enhance their survival