Question 1

Which of the following best explains why the appearance of oxygen in Earth's atmosphere is considered a major evolutionary event?

Accepted Answer

Oxygen reacted with iron in the oceans, leading to the formation of banded iron formations and causing a mass extinction of anaerobic organisms.

Question 2

Which of the following is a correct interpretation of the molecular clock hypothesis?

Accepted Answer

Molecular clocks use the rate of genetic mutations to estimate the timing of evolutionary events, calibrated with known fossil ages.

Question 3

Which of the following statements about the endosymbiotic theory is supported by evidence?

Accepted Answer

Mitochondria and chloroplasts have circular genomes similar to those of prokaryotes.

Question 4

A researcher finds a fossilized structure that resembles modern stromatolites. What does this suggest about the fossil?

Accepted Answer

It is likely evidence of ancient microbial mats formed by photosynthetic bacteria.

Question 5

Which of the following best describes a monophyletic group (clade)?

Accepted Answer

A group that includes a common ancestor and all of its descendants.

Question 6

Which of the following is an example of an analogous trait rather than a homologous trait?

Accepted Answer

The wings of bats and the wings of birds, both used for flight but evolved independently.

Question 7

Which of the following best explains why the fossil record is incomplete?

Accepted Answer

Many organisms lack hard parts and are unlikely to fossilize.

Question 8

Which of the following events is associated with the Cambrian explosion?

Accepted Answer

Rapid diversification of most major animal phyla.

Question 9

Which of the following is a synapomorphy that defines mammals as a clade?

Accepted Answer

Presence of hair and mammary glands.

Question 10

A biologist is constructing a phylogenetic tree using DNA sequence data. Which of the following is a key advantage of using molecular data over morphological data?

Accepted Answer

Molecular data can reveal evolutionary relationships among organisms with few obvious morphological differences.

Question 11

Which of the following best describes the relationship between plants and fungi during the colonization of land?

Accepted Answer

Plants and fungi formed symbiotic relationships, with plants providing carbon and nutrients and fungi providing minerals.

Question 12

Which of the following is a correct statement about extinction events?

Accepted Answer

Mass extinction events have repeatedly reshaped the diversity of life on Earth.

Question 13

Which of the following is a shared derived character (synapomorphy) for the clade of vertebrates?

Accepted Answer

Presence of a vertebral column.

Question 14

Which of the following best describes the process of cladistics?

Accepted Answer

Cladistics groups organisms based on shared derived characteristics to infer evolutionary relationships.

Question 15

Which of the following is an example of a paraphyletic group?

Accepted Answer

Reptiles, excluding birds.

Question 16

If a molecular clock shows a mutation rate of $$1 	imes 10$$^{-8}$$ mutations per site per year, and two species differ by 0.02 substitutions per site, approximately how many years ago did they diverge? (Assume the rate applies to both lineages equally.)

Accepted Answer

$$1 	imes 10$$^{8}$$ years

Question 17

Which of the following is a real-world consequence of the oxygenation of Earth's atmosphere by photosynthetic organisms?

Accepted Answer

The formation of rusted iron deposits known as banded iron formations.

Question 18

Which of the following best explains why similarity does not always indicate close evolutionary relationship?

Accepted Answer

Similar traits can evolve independently in unrelated groups due to convergent evolution.

Question 19

Which of the following is a correct statement about the hierarchical classification system introduced by Linnaeus?

Accepted Answer

It organizes species into nested categories such as kingdom, phylum, class, order, family, genus, and species.

Question 20

Which of the following is a plausible reason why multicellularity evolved multiple times in different lineages?

Accepted Answer

Multicellularity provides advantages such as cell specialization and increased size, which can evolve independently in different groups.

Chapter 26: The History of Life on Earth & Phylogeny and the Tree of Life – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards