General Ecology Chapter 2

Question 1

What is the Malthusian theory of population?

Answer 1

Earth was not overrun by humans, population growth must be limited by food shortage, disease, war, or conscious control

Question 2

What is natural selection?

Answer 2

Better-adapted organisms would acquire more resources and leave more offspring

Question 3

What is adaptation?

Answer 3

Given an evolutionary time span, a population’s characteristics change to make its members better suited to their environment

Question 4

What are characters?

Answer 4

many readily available varieties that differed in visible characteristics

Question 5

What is self-fertilization?

Answer 5

makes it easy to produce plants that breed true for a given trait meaning that the trait does not vary from generation to generation

Question 6

What is a true-breeding line?

Answer 6

A variety that continues to exhibit the same trait after several generations of self-fertilization

Question 7

What is cross-fertilization or hybridization?

Answer 7

When two individuals with different characteristics are mated or crossed to each other and the offspring are referred to as hybrids

Question 8

What is the P generation?

Answer 8

The true-breeding parents

Question 9

What is the F1 generation?

Answer 9

The first generation offspring of a P cross

Question 10

What are monohybrids?

Answer 10

When the true-breeding parents differ with regard to a single trait to their F1 offspring

Question 11

What is the F2 generation?

Answer 11

F1 monohybrids to self-fertilize producing a generation

Question 12

What are dominants?

Answer 12

the displayed trait

Question 13

What are recessive?

Answer 13

a trait that is masked by the presence of a dominant trait

Question 14

What are genes?

Answer 14

genetic determinants of traits

Question 15

What are alleles?

Answer 15

the gene for each trait has 2 variant forms

Question 16

What does segregate mean?

Answer 16

separate from each other so that each sperm or egg carries only one allele

Question 17

What is Mendel’s law of segregation?

Answer 17

The idea that the two copies of a gene segregate from each other during transmission from parent to offspring

Question 18

What is a genotype?

Answer 18

the genetic composition of an individual

Question 19

What is a homozygous individual?

Answer 19

an individual with two identical copies of a gene

Question 20

What is a heterozygous individual?

Answer 20

carries 2 different alleles of the same gene

Question 21

What is a phenotype?

Answer 21

refers to the physical characteristics of an organisms which are the result of the expression of its genes

Question 22

What are point-shift mutations?

Answer 22

exchange a single nucleotide for another

Question 23

What are frameshift mutations?

Answer 23

involves the addition or deletion of nucleotides

Question 24

What are genotype frequencies? What are the allele and genotype frequency

Answer 24

genotypes in a population; allele frequency: number of copies of a specific allele in a population/ total number of all alleles for that gene in a population; genotype frequency: number of individuals with a particular genotype in a population/ total number of individuals in a population

Question 25

What is the Hardy-Weinberg equation?

Answer 25

(p+q)^2=1

Question 26

What is inbreeding?

Answer 26

mating between closely related relatives, increases the chances of both parents carrying the same harmful alleles and thus of the production of homozygous offspring that exhibit the effects

Question 27

The better-adapted organism acquires more resources and leaves more offspring than a less-well-adapted organism. This idea best conveys the theme of:

Answer 27

Natural selection

Question 28

The theory of evolution by natural selection was proposed by:

Answer 28

Charles Darwin and Alfred Wallace

Question 29

The color change that has occurred in certain populations of the peppered moth, Biston betularia in industrial areas of Europe is known as:

Answer 29

Industrial melanism

Question 30

The first generation offspring of true-breeding parents are termed the:

Answer 30

P generation

Question 31

The 2 variant forms of a gene are called:

Answer 31

Alleles

Question 32

Which term refers to the genetic composition of an individual?

Answer 32

Gentype

Question 33

When a chromosome breaks in 2 places and the middle segment turns around and re-fuses with the other 2 pieces, this is termed:

Answer 33

Inversion

Question 34

What is the expected F2 genotypic ratio of a monohybrid cross?

Answer 34

3:1

Question 35

Approximately what percentage of genetic variation remains in a population of 25 individuals after 3 generations?

Answer 35

94

Question 36

Small populations are threatened by the loss of genetic diversity from:

Answer 36

Genetic drift