Question 1

During meiosis, how does ploidy change from the beginning to the end of the process, and what is the biological significance of this change?

Accepted Answer

Ploidy decreases from diploid to haploid, ensuring that gametes have half the chromosome number of somatic cells, which is restored at fertilization.

Question 2

A pea plant with genotype $$YyRr ($$yellow, round seeds) is crossed with another $$YyRr$$ plant. According to Mendelian genetics, what is the expected phenotypic ratio in the F2 generation for seed color and shape?

Accepted Answer

9 yellow round : 3 yellow wrinkled : 3 green round : 1 green wrinkled

Question 3

Which of the following best defines evolution in a biological context?

Accepted Answer

A change in allele frequencies in a population over generations.

Question 4

A population of 1000 beetles has genotype frequencies: $$AA = 0.36$$, $$Aa = 0.48$$, $$aa = 0.16. $$What are the allele frequencies for $$A$$ and $$a$$?

Accepted Answer

$$A = 0.6$$, $$a = 0.4$$

Question 5

Which of the following is an example of directional selection, and how might it relate to character displacement in competing species?

Accepted Answer

A population of moths where darker individuals are favored in polluted environments, shifting the average coloration over generations.

Question 6

Which of the following statements about genetic drift is correct?

Accepted Answer

Genetic drift has a stronger effect in small populations and can lead to loss of alleles regardless of fitness.

Question 7

Which species concept is most useful for identifying cryptic species that are morphologically similar but genetically distinct, and what is a limitation of this concept?

Accepted Answer

Phylogenetic species concept; it may lead to recognizing too many species due to minor genetic differences.

Question 8

Why is no single phylogeny considered absolutely correct, and how can convergent evolution complicate phylogenetic analysis?

Accepted Answer

Phylogenies are hypotheses that can be revised with new data, and convergent evolution can result in similar traits in unrelated lineages.

Question 9

How do bacteria of different species share genes, and what is the evolutionary significance of this process?

Accepted Answer

Through horizontal gene transfer, which allows rapid acquisition of new traits.

Question 10

According to the endosymbiotic theory, which event explains why all eukaryotes perform cellular respiration?

Accepted Answer

The engulfment of an aerobic bacterium, which became the mitochondrion.

Question 11

Which of the following is a synapomorphy uniting all angiosperms, and how does this trait contribute to their evolutionary success?

Accepted Answer

Seeds enclosed in fruit, which aids in dispersal by animals.

Question 12

How do fungi obtain matter and energy, and what major ecological role do they play?

Accepted Answer

By external digestion and absorption; they are major decomposers in ecosystems.

Question 13

Which of the following best describes the difference between exponential and logistic population growth?

Accepted Answer

Exponential growth occurs when resources are unlimited, while logistic growth includes a carrying capacity $$K$$ that limits population size.

Question 14

Which of the following is an example of an ultimate cause of animal behavior?

Accepted Answer

A bird sings to attract mates, increasing its reproductive success.

Question 15

Hamilton’s rule predicts that altruism is favored when $$rB \u003e C. In a $$population of ground squirrels, a female warns her relatives of a predator. If the cost to the actor is 0.2, the benefit to the recipient is 0.5, and the coefficient of relatedness is 0.5, will this behavior be favored by natural selection?

Accepted Answer

Yes, because $$0.5 	imes 0.5 = 0.25 \u003e 0.2$$

Question 16

Which of the following best describes how matter and energy flow through terrestrial ecosystems?

Accepted Answer

Energy flows one way, decreasing at each trophic level, while matter cycles among organisms and the environment.

Question 17

Which of the following is NOT a component of biodiversity?

Accepted Answer

Population growth rate

Question 18

How does gene flow affect genetic variability and fitness in populations?

Accepted Answer

Gene flow can increase genetic variability by introducing new alleles, and may increase or decrease fitness depending on the alleles introduced.

Question 19

Which of the following best explains why higher biodiversity is generally better for ecosystem resilience?

Accepted Answer

Higher biodiversity increases the likelihood that some species can maintain ecosystem functions after disturbance.

Question 20

Which of the following is a real-world example of how human activities have altered a biogeochemical cycle, and what is a consequence of this alteration?

Accepted Answer

Fertilizer runoff increases nitrogen in aquatic systems, leading to eutrophication and dead zones.

Comprehensive Study Guide: Evolution, Diversity, and Ecology (BIO 1331, Ch. 13-14, 22-32, 49-54)

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