Exam 1 Spinoff

Question 1

What key observation inspired Darwin’s theory of evolution?

Answer 1

Variation among species on the Galápagos Islands during his voyage on the HMS Beagle.

Question 2

What is natural selection?

Answer 2

The process where organisms with favorable traits survive and reproduce more successfully.

Question 3

What are Darwin’s three major pieces of evidence for evolution?

Answer 3

1) Fossils, 2) Homologies between species, 3) Artificial selection.

Question 4

What is the difference between natural and artificial selection?

Answer 4

Natural selection is environment-driven, artificial selection is human-directed.

Question 5

What was Lamarck’s incorrect evolutionary theory?

Answer 5

Use and disuse & inheritance of acquired characteristics.

Question 6

What experiment did Weismann use to disprove Lamarckism?

Answer 6

Cutting off rat tails for 20 generations—offspring were still born with tails.

Question 7

What is the smallest biological unit that can evolve?

Answer 7

A population.

Question 8

Define gene pool.

Answer 8

All alleles in all individuals in a population.

Question 9

What is the Hardy-Weinberg principle?

Answer 9

Allele frequencies remain constant in a population unless disturbed by external factors.

Question 10

What are the five conditions for Hardy-Weinberg equilibrium?

Answer 10

1) Large population, 2) No migration, 3) No mutation, 4) Random mating, 5) No natural selection.

Question 11

What are causes of microevolution?

Answer 11

Mutation, genetic drift, gene flow, natural selection, and nonrandom mating.

Question 12

Define genetic drift.

Answer 12

Random changes in allele frequencies, especially in small populations.

Question 13

What is balanced polymorphism?

Answer 13

Maintaining multiple phenotypes in a population.

Question 14

What is speciation?

Answer 14

The formation of new species.

Question 15

Differentiate anagenesis and cladogenesis.

Answer 15

Anagenesis: species changes into a new one. Cladogenesis: branching off into multiple species.

Question 16

What is sympatric speciation?

Answer 16

Speciation without geographic isolation, often through polyploidy.

Question 17

Define polyploidy and its types.

Answer 17

More than two chromosome sets. Autopolyploidy: duplication in same species; allopolyploidy: hybrid of different species.

Question 18

What are prezygotic isolating mechanisms?

Answer 18

Prevent mating or fertilization: habitat, temporal, behavioral, mechanical, gametic.

Question 19

What are postzygotic isolating mechanisms?

Answer 19

Prevent viable offspring: hybrid inviability or sterility.

Question 20

What are the two tempos of speciation?

Answer 20

Punctuated equilibrium (rapid bursts), and gradualism (slow continuous change).

Question 21

What is a zygote?

Answer 21

A fertilized egg resulting from fusion of sperm and egg.

Question 22

Difference between protostomes and deuterostomes?

Answer 22

Protostomes: blastopore becomes mouth; Deuterostomes: blastopore becomes anus.

Question 23

What are the three types of eggs by yolk distribution?

Answer 23

Isolecithal (little yolk), mesolecithal (moderate yolk), telolecithal (large yolk).

Question 24

What are the three germ layers and what do they form?

Answer 24

Ectoderm: skin/nervous, Mesoderm: muscle/bone, Endoderm: digestive/respiratory.

Question 25

What is neurulation?

Answer 25

Formation of the nervous system in vertebrates.

Question 26

Define natural selection.

Answer 26

The process by which organisms better adapted to their environment tend to survive and produce more offspring.

Question 27

Define artificial selection.

Answer 27

Selective breeding of organisms by humans to encourage the occurrence of desirable traits.

Question 28

Define evolution.

Answer 28

The change in the genetic composition of a population over successive generations.

Question 29

Define gene pool.

Answer 29

The complete set of genetic information within all individuals in a population.

Question 30

Define genetic drift.

Answer 30

Random change in allele frequencies in a small population.

Question 31

Define gene flow.

Answer 31

Transfer of alleles from one population to another through migration.

Question 32

Define mutation.

Answer 32

A change in the DNA sequence of an organism.

Question 33

Define speciation.

Answer 33

The formation of new and distinct species in the course of evolution.

Question 34

Define Hardy-Weinberg equilibrium.

Answer 34

A condition in which a population’s allele frequencies remain constant over generations unless disturbed.

Question 35

Define polyploidy.

Answer 35

A condition in which an organism has more than two complete sets of chromosomes.

Question 36

Define zygote.

Answer 36

A fertilized egg cell formed by the union of a sperm and an egg.

Question 37

Define gastrulation.

Answer 37

The process during embryonic development that forms the three germ layers.

Question 38

Define neurulation.

Answer 38

The formation of the neural tube in early embryonic development.

Question 39

Define ectoderm.

Answer 39

The outermost germ layer, which gives rise to the skin and nervous system.

Question 40

Define mesoderm.

Answer 40

The middle germ layer, which gives rise to muscles, bones, and the circulatory system.

Question 41

Define endoderm.

Answer 41

The innermost germ layer, which forms the lining of the digestive and respiratory systems.