Genetics and Evolution

Question 1

The combination of alleles one has at a given genetic locus.

Answer 1

Genotype

Question 2

The observable manifestation of a genotype.

Answer 2

Phenotype

Question 3

One dominant allele and one recessive allele.

Answer 3

Complete Dominance

Question 4

More than one dominant allele.

Answer 4

Codominance

Question 5

Has no dominant alleles; heterozygotes has intermediate phenotypes.

Answer 5

Incomplete Dominance

Question 6

The proportion of a population with a given genotype who express the same phenotype.

Answer 6

Penetrance

Question 7

The varying phenotypic manifestations of a given genotype.

Answer 7

Expressivity

Question 8

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 8

Mendel’s First Law (of segregation)

Question 9

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

Answer 9

Mendel’s Second Law (of independent assortment)

Question 10

This experiment demonstrated the transforming principle, converting non-virulent bacteria into virulent bacteria by exposure to heat-killed virulent bacteria.

Answer 10

Griffith Experiment

Question 11

This experiment demonstrated that DNA is genetic material because degradation of DNA led to cessation of bacterial transformation.

Answer 11

Avery-MacLeod-McCarty Experiment

Question 12

This experiment confirmed that DNA is genetic material because only radiolabeled DNA could be found in bacteriophage-infected bacteria.

Answer 12

Hershey-Chase Experiment

Question 13

What are some nucleotide mutations?

Answer 13

• Point Mutations

- Frameshift Mutations

Question 14

The substituting of one nucelotide for another.

Answer 14

Point Mutations

Question 15

Moving the three-letter transcriptional reading frame.

Answer 15

Frameshift Mutations

Question 16

A mutation that has no effect on the protein.

Answer 16

Silent Mutation

Question 17

The substitution of one amino acid for another.

Answer 17

Missense Mutation

Question 18

The substitution of a stop codon for an amino acid.

Answer 18

Nonsense Mutation

Question 19

Result in a shift in the reading frame of genes, leading to changes for all downstream amino acids.

Answer 19

Insertions/Deletions

Question 20

Mutations that include much larger-scales and affect whole segments of DNA.

Answer 20

Chromosomal Mutations

Question 21

What are some chromosomal mutations?

Answer 21

• Deletion mutations
• Duplication mutations
• Inversion mutations
• Insertion mutations
• Translocation mutations

Question 22

Occurs when a large segment of DNA is lost.

Answer 22

Deletion Mutations

Question 23

Occurs when a segment of DNA is copied multiple times.

Answer 23

Duplication Mutations

Question 24

Occurs when a segment of DNA is reversed.

Answer 24

Inversion Mutations

Question 25

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

Answer 25

Insertion Mutations

Question 26

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

Answer 26

Translocation Mutations

Question 27

A flow of genes between species through hybrid offspring.

Answer 27

Genetic Leakage

Question 28

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

Answer 28

Genetic Drift

Question 29

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

Answer 29

Founder Effect

Question 30

The likelihood of two alleles being separated during crossing over in meiosis.

Answer 30

Recombination Frequency (theta)

Question 31

States that if a population meets certain criteria (aimed at a lack of evolution), then the allele frequencies will remain constant.

Answer 31

Hardy-Weinburg Principle

Question 32

Accounts for mutation and recombination as mechanisms of variation and considers differential reproduction to be the mechanism of reproductive success.

Answer 32

Modern Synthesis Model (Neo-Darwinism)

Question 33

Considers an organism’s success to be based on the number of offspring, sucess in supporting offspring and the ability of the offspring to then support others.

Answer 33

Inclusive Fitness

Question 34

Keeps phenotypes in a narrow range, excluding extremes.

Answer 34

Stabilizing Selection

Question 35

Moves the average phenotype toward one extreme.

Answer 35

Directional Selection

Question 36

Moves toward two different phenotypes at extremes and can lead to speciation.

Answer 36

Disruptive Selection

Question 37

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

Answer 37

Adaptive Radiation

Question 38

Occurs when two species sharing a common ancestor become more different.

Answer 38

Divergent Evolution

Question 39

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

Answer 39

Parallel Evolution

Question 40

Occurs when two species NOT sharing a recent ancestor evolve to become more similar due to analogous selection pressures.

Answer 40

Convergent Evolution

Question 41

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 41

Molecular Clock Model