Chapter 7

Question 1

Descent with modification?

Answer 1

“Evolution” that all living species have descended from a succession of ancestral species, each of which accumulated modifications that helped them survive in their habitat.

Question 2

Natural selection

Answer 2

The process by which organisms with certain traits are more likely to survive and reproduce than other organisms.

Question 3

Darwin made two important points.

Answer 3

Modern species have descended from common ancestors.

Natural selection is the mechanism of evolution.

Question 4

Individuals evolve. T or F?

Answer 4

False. Evolution is a generation to generation change in populations.

Question 5

Natural selection works with heritable traits only. T or F?

Answer 5

True. Only traits that are encoded within genes and passed on to the next generation can possibly affect the reproductive success of that generation.

Question 6

Evolution has a goal. T or F?

Answer 6

False. Evolution is always driven by the local environmental conditions at that time.

Question 7

Adaptation

Answer 7

The accumulation of favorable traits in a population over time.

Question 8

Over many generations, continuous natural selection within a population will result in ________.

Answer 8

Evolution.

Question 9

The selective breeding of domesticated crops and animals.

Answer 9

Artificial selection.

Question 10

Naturally occurring drugs that kill bacteria.

Answer 10

Antibiotics.

Question 11

Fossil record

Answer 11

The ordered sequence of fossils found in layers of rock.

Question 12

Radiometric dating

Answer 12

A way to determine the age of fossils. Based on the breakdown of the radioactive isotopes found in all living matter.

Question 13

Biogeography

Answer 13

The study of the geographic distribution of species.

Question 14

Comparisons of the body structures of modern organisms.

Answer 14

Comparative anatomy.

Question 15

All organisms use genes encoded in their hereditary DNA to produce _________.

Answer 15

Proteins.

Question 16

Bioinformatics

Answer 16

The use of computational tools to make biological comparisons.

Question 17

What’s the smallest unit that can evolve?

Answer 17

A population.

Question 18

Gene pool

Answer 18

All of the forms of all the genes in a population at any one time.

Question 19

Generation to generation change in the gene pool.

Answer 19

microevolution.

Question 20

Shuffles existing genes. Produces new arrangements of existing genes.

Answer 20

Sexual recombination.

Question 21

Darwinian fitness.

Answer 21

The contribution that an individual makes to the gene pool of the next generation in comparison to the contributions from other individuals.

Question 22

What’s the primary mechanism to changes in a gene pool over successive generations?

Answer 22

Natural Selection.

Question 23

4 mechanisms, besides natural selection, that can lead to changes in the gene pool.

Answer 23

Bottleneck and founder effect.
Gene flow.
Sexual Selection.
Genetic Drift.

Question 24

Genetic Drift

Answer 24

A change in a gene pool due to chance.

Question 25

Bottleneck effect / founder effect.

Answer 25

A change in the gene pool due to a significant reduction in population size.

Question 26

Gene flow

Answer 26

When individuals migrate into or emigrate out of a population.

Question 27

Sexual Selection

Answer 27

Form of natural selection whereby certain individuals are more likely to attract mates and, therefore, have more offspring.

Question 28

A population that is capable of interbreeding to produce healthy offspring that can themselves reproduce.

Answer 28

Species.

Question 29

Reproductive barriers

Answer 29

Prevent members of different species from interbreeding.

Question 30

List of reproductive barriers

Answer 30

``` Behavioral Isolation. Mating Time Differences. Habitat isolation. Mechanical Incompatibility. Gametic incompatibility. Hybrid weakness. ```

Question 31

Behavioral Isolation

Answer 31

Species identify each other through specific ritual, markings, or smells.

Question 32

Mating time differences

Answer 32

Species may be only able to reproduce at particular times.

Question 33

Habitat isolation

Answer 33

Species may never meet due to living in different habitats.

Question 34

Mechanical incompatibility

Answer 34

Species cannot mate because of incompatible anatomies.

Question 35

Gametic incompatibility

Answer 35

The gametes of each species can't fertilize each other.

Question 36

Hybrid weakness

Answer 36

The hybrid offspring of two different species will likely be unfit in some way.

Question 37

The identification, naming, and classification of a species.

Answer 37

Taxonomy.

Question 38

All life is classified into one of three large groups called ______ based on cell type.

Answer 38

Domains.

Question 39

Taxonomic hierarchy

Answer 39

ordered series of progressively smaller categories. The hierarchy ends with the species name.

Question 40

Three-domain system

Answer 40

The preferred taxonomic system among biologists.

Question 41

What are the last two groups in the taxonomic hierarchy to identify a species?

Answer 41

Genus Species.