Biology Chapter 12: Evolution and Genetics (4 Stars)

Question 1

Chromosomes contain genes in a _____ sequence.

Answer 1

linear

Question 2

_____ are alternative forms of a gene.

Answer 2

Alleles

Question 3

A ______ allele requires only one copy to be expressed.

Answer 3

dominant

Question 4

A recessive allele requires ___ copies to be expressed.

Answer 4

two

Question 5

A ______ is the combination of alleles one has at a given genetic locus.

Answer 5

genotype

Question 6

Having two of the same allele is termed ______

Answer 6

homozygous.

Question 7

Having two different alleles is termed _______

Answer 7

heterozygous.

Question 8

Having only one allele is termed _______ (such as male sex chromosomes).

Answer 8

hemizygous

Question 9

A _______ is the observable manifestation of a genotype.

Answer 9

phenotype

Question 10

There are different patterns of ______

Answer 10

dominance.

Question 11

______ has one dominant allele and one recessive allele.

Answer 11

Complete dominance

Question 12

______ has more than one dominant allele.

Answer 12

Codominance

Question 13

______ has no dominant alleles; heterozygotes have intermediate phenotypes.

Answer 13

Incomplete dominance

Question 14

______ is the proportion of a population with a given genotype who express the phenotype.

Answer 14

Penetrance

Question 15

_____ refers to the varying phenotypic manifestations of a given genotype.

Answer 15

Expressivity

Question 16

______ states that an organism has two alleles for each gene, which segregate during meiosis, resulting in gametes carrying only one allele for a trait.

Answer 16

Mendel’s first law (of segregation)

Question 17

_______states that the inheritance of one allele does not influence the probability of inheriting a given allele for a different trait.

Answer 17

Mendel’s second law (of independent assortment)

Question 18

The Griffith experiment demonstrated the ______, converting non-virulent bacteria into virulent bacteria by exposure to heat-killed virulent bacteria.

Answer 18

transforming principle

Question 19

The Avery–MacLeod–McCarty experiment demonstrated that DNA is the genetic material because degradation of DNA led to a cessation of _____

Answer 19

bacterial transformation.

Question 20

The Hershey–Chase experiment confirmed that DNA is the genetic material because only ____ DNA could be found in bacteriophage infected bacteria.

Answer 20

radiolabeled

Question 21

All of the alleles in a given population constitute the _____

Answer 21

gene pool.

Question 22

_____ are changes in DNA sequence.

Answer 22

Mutations

Question 23

______ include point mutations (the substituting of one nucleotide for another) and frameshift mutations (moving the three-letter transcriptional reading frame).

Answer 23

Nucleotide mutations

Question 24

A _______ has no effect on the protein.

Answer 24

silent mutation

Question 25

A ______ mutation results in the substitution of one amino acid for another.

Answer 25

missense mutation

Question 26

A ______ mutation results in the substitution of a stop codon for an amino acid.

Answer 26

nonsense mutation

Question 27

Insertions and deletions result in a ____ in the reading frame, leading to changes for all downstream amino acids.

Answer 27

shift

Question 28

______ include much larger-scale mutations affecting whole segments of DNA.

Answer 28

Chromosomal mutations

Question 29

______ occur when a large segment of DNA is lost.

Answer 29

Deletion mutations

Question 30

_____ occur when a segment of DNA is copied multiple times.

Answer 30

Duplication mutations

Question 31

_____ occur when a segment of DNA is reversed.

Answer 31

Inversion mutations

Question 32

_____ occur when a segment of DNA is moved from one chromosome to another.

Answer 32

Insertion mutations

Question 33

______ occur when a segment of DNA is swapped with a segment of DNA from another chromosome.

Answer 33

Translocation mutations

Question 34

______ is a flow of genes between species through hybrid offspring.

Answer 34

Genetic leakage

Question 35

______ occurs when the composition of the gene pool changes as a result of chance.

Answer 35

Genetic drift

Question 36

The ______ results from bottlenecks that suddenly isolate a small population, leading to inbreeding and increased prevalence of certain homozygous genotypes.

Answer 36

founder effect

Question 37

_____ visually represent the crossing of gametes from parents to show relative genotypic and phenotypic frequencies.

Answer 37

Punnett squares

Question 38

A ______ cross accounts for one gene; a dihybrid cross accounts for two genes.

Answer 38

monohybrid

Question 39

In sex-linked crosses, sex chromosomes are usually used to indicate sex as well as _____

Answer 39

genotype.

Question 40

The ______ states that if a population meets certain criteria (aimed at a lack of evolution), then the allele frequencies will remain constant (Hardy–Weinberg equilibrium). Evolution

Answer 40

Hardy–Weinberg principle

Question 41

______ states that chance variations exist between individuals, and that advantageous variations—those that increase an individual’s fitness for the environment—afford the most opportunity for reproductive success.

Answer 41

Natural selection

Question 42

The modern synthesis model ______ accounts for mutation and recombination as mechanisms of variation and considers differential reproduction to be the mechanism of reproductive success.

Answer 42

(neo-Darwinism)

Question 43

_____ considers an organism’s success to be based on the number of offspring, success in supporting offspring, and the ability of the offspring to then support others; survival of offspring or relatives ensures continuation of genes in subsequent generations.

Answer 43

Inclusive fitness

Question 44

_____ equilibrium considers evolution to be a very slow process with intermittent rapid bursts of evolutionary activity.

Answer 44

Punctuated

Question 45

Stabilizing selection keeps ____ in a narrow range, excluding extremes.

Answer 45

phenotypes

Question 46

______ moves the average phenotype toward one extreme.

Answer 46

Directional selection

Question 47

______ moves toward two different phenotypes at the extremes and can lead to speciation.

Answer 47

Disruptive selection

Question 48

______ is the rapid emergence of multiple species from a common ancestor, each of which occupies its own ecological niche.

Answer 48

Adaptive radiation

Question 49

A species is the largest group of organisms capable of breeding to form _____ offspring. Species are reproductively isolated from each other by pre- or postzygotic mechanisms.

Answer 49

fertile

Question 50

___ species can evolve with different relationship patterns.

Answer 50

Two

Question 51

_____ evolution occurs when two species sharing a common ancestor become more different.

Answer 51

Divergent evolution

Question 52

______ evolution occurs when two species sharing a common ancestor evolve in similar ways due to analogous selection pressures.

Answer 52

Parallel

Question 53

_____ evolution occurs when two species not sharing a recent ancestor evolve to become more similar due to analogous selection pressures.

Answer 53

Convergent

Question 54

According to the ______ model, the degree of difference in the genome between two species is related to the amount of time since the two species broke off from a common ancestor.

Answer 54

molecular clock model