Section 23.1
1. What evolves organisms, or populations?
2. What consistently improves the match between organisms and their
environment?
3. Who wrote the first paper on inheritance?
4. Discrete characteristics are usually determined by how many gene loci?
5. What is a translocation of a gene?
6. What are the 3 main mechanisms that can cause allele frequency to
change?
7. Clines in a population usually result from ________ _________.
8. Chromosomal changes that _______, ________, or _________ many loci
at once are usually harmful.
9. In a multicellular organism where does the mutation have to occur to be
past on to the offspring?
10.What is a change of as little as one base in a gene?
11.What are the two ways to measure genetic variation?
12.Sexual reproduction can result in ______ _________ as existing genes
are arranged in new ways.
13.What is the name of the book that provided abundant evidence that life on
Earth has evolved over time and proposed natural selection as the primary
mechanism for that change?
14.What is a locus?
15.Are mutation rates low or high in plants and animals?
16.What is microevolution?
17.What is genetic variation?
18.What is average heterozygosity?
19.What is geographic variation?
20.What is a cline?
Section 23.2
1. What are the five conditions for Hardy-Weinberg Equilibrium?
2. What is the Hardy-Weinberg equation?
3. What does p2 represent?
4. What is p?
5. What does q2 represent?
6. What is q?
7. What is 2pq?
8. Is Hardy-Weinberg Equilibrium common in natural populations?
9. If p=0.2, what does q= ?
10.If q=0.9, what does p= ?
11.If only one allele exists for a particular locus in a population, that allele is
said to be _____.
12.Where is isolation common?
13.What were the occupations of Hardy and Weinberg?
14.What year was the Hardy-Weinberg Principle developed?
15.Each genotype has a distinct _____ in incomplete dominance.
16.What is a population?
17.What is a gene pool?
18.What is the Hardy-Weinberg principle?
Section 23.3
1. What are some changes that cause a bottleneck effect?
2. What is gene flow?
3. Genetic drift can cause allele frequencies to change at _________.
4. What is intersexual selection also called?
5. Give one effect of genetic drift.
6. Define genetic drift.
7. What is the founder effect?
8. What is the bottleneck effect?
Section 23.4
1. Large black bears survived periods of extreme cold better than smaller
ones, and so became more common. This is an example of...
2. Birth weights of most humans lie in a narrow range, as those babies who
are very large or very small have higher mortality. This is an example of...
3. Does natural selection act more directly on an individual’s phenotype or
genotype?
4. People who carry one sickle cell allele are resistant to malaria. This is an
example of...
5. A peacock shows off his tail feathers and competes with other males to
attract a mate. This is an example of...
Answers
Section 23.1
1. Populations
2. Natural Selection
3. Gregor Mendel
4. One
5. When a gene is moved out of or into a DNA sequence.
6. Natural selection, genetic drift, and gene flow
7. Natural selection
8. Delete, disrupt, rearrange
9. A mutation in cell lines that produce gametes.
10.Point mutation
11.Gene variability & nucleotide variability
12.Genetic variation
13.The Origin of Species
14.A specific place along the length of a chromosome where a given gene is
located
15.Low
16.Evolutionary change below the species level
17.Differences among the individuals in the composition of their genes or
other DNA segments
18.The percentage, on average, of a population’s loci that are heterozygous
in members of the population.
19.Differences between the gene pools of geographically separate
populations or population subgroups
20.A graded change in character along a geographic axis.
Section 23.2
1. •No mutations
•Random mating
•No natural selection
•Extremely large population size
•No gene flow
2. p2 + 2pq + q2 = 1
3. The expected frequency of the homozygous dominant genotype.
4. The expected frequency of the dominant allele.
5. The expected frequency of the homozygous recessive genotype.
6. The expected frequency of the recessive allele.
7. The expected frequency of the heterozygous genotype.
8. No
9. 0.8
10.0.1
11.Fixed
12.Islands
13.Mathematician & Physician
14.1908
15.Phenotype
16.A group of individuals of the same species that live in the same area and
interbreed, producing fertile offspring.
17.The aggregate of all copies of every type of allele at all loci in every
individual in a population.
18.The principle that frequencies of alleles and genotypes in a population
remain constant from generation to generation, provided that only
Mendelain segregation and recombination of alleles are at work.
Section 23.3
1. Fire or flood
2. Transfer of alleles into or out of a population due to the movement of
fertile individuals or their gametes.
3. Random
4. Mate choice
5. 1) Genetic drift is significant in small populations
2) Genetic drift can cause allele frequencies to change at random
3) Genetic drift can lead to a loss of genetic variation within a population
4) Genetic drift can cause harmful alleles to become fixed
6. A process in which chance events cause unpredictable fluctuations in
allele frequencies from one generation to the next. Effects of genetic drift
are most pronounced in small populations.
7. Genetic drift that occurs when a few individuals become isolated from a
larger population whose gene pool composition is not reflective of that of
the original population.
8. Genetic drift that occurs when the size of a population is reduced, as by a
natural disaster or human actions.
Section 23.4
1. Directional selection
2. Stabilizing selection
3. Phenotype
4. Heterozygote advantage
5. Intrasexual selection