Question 1

Which of the following statements best explains why phylogenetic trees are considered hypotheses?

Accepted Answer

Because they are constructed using available data and can be revised as new evidence emerges.

Question 2

A scientist is comparing two phylogenetic trees for a group of birds. Tree A requires 5 character transitions, while Tree B requires 8. According to the principle of parsimony, which tree is preferred and why?

Accepted Answer

Tree A, because it requires fewer evolutionary changes.

Question 3

Which of the following is an example of a postzygotic reproductive barrier?

Accepted Answer

A horse and a donkey mate and produce a sterile mule.

Question 4

A population of beetles is split by the formation of a new river, preventing gene flow between the two groups. Over time, the groups diverge genetically and morphologically. What type of speciation is this an example of?

Accepted Answer

Allopatric speciation

Question 5

A fossil contains $$\frac{1}{16} of $$the original amount of a radioactive parent isotope. If the half-life of the isotope is 2 million years, how old is the fossil?

Accepted Answer

$$8$$ million years

Question 6

Which process is primarily responsible for the increase in atmospheric oxygen during the Precambrian, and which organisms were key to this change?

Accepted Answer

Photosynthesis by cyanobacteria

Question 7

Which of the following best describes the difference between the Biological Species Concept and the Morphological Species Concept?

Accepted Answer

The Biological Species Concept defines species by their ability to interbreed, while the Morphological Species Concept defines species by physical characteristics.

Question 8

Which of the following events occurred during the Paleozoic Era?

Accepted Answer

Colonization of land by plants

Question 9

Which group of organisms is most likely to undergo sympatric speciation due to polyploidy?

Accepted Answer

Plants

Question 10

Which of the following is a shared derived character (synapomorphy) of all chordates?

Accepted Answer

Notochord

Question 11

Which of the following best explains why DNA data can sometimes produce more accurate phylogenetic trees than phenotypic data?

Accepted Answer

DNA data are less likely to be affected by convergent evolution than phenotypic traits.

Question 12

Which of the following is a correct example of a photoautotroph and a chemoheterotroph?

Accepted Answer

Photoautotroph: cyanobacterium; Chemoheterotroph: human

Question 13

Which of the following is NOT a trait shared by all eukaryotes but absent in Bacteria and Archaea?

Accepted Answer

Peptidoglycan cell wall

Question 14

Which adaptation allowed plants to reproduce successfully away from water and led to the diversification of reptiles?

Accepted Answer

Evolution of the amniotic egg

Question 15

Which of the following best describes the main evidence for the asteroid impact hypothesis for the K-Pg extinction?

Accepted Answer

A worldwide layer of iridium-rich clay dating to 66 mya

Question 16

Which of the following animal phyla is defined by having a soft body, often with a calcium carbonate shell, and includes snails and octopuses?

Accepted Answer

Mollusca

Question 17

A scientist finds a fossil with bilateral symmetry, a notochord, and evidence of an amniotic egg. To which group does this organism most likely belong?

Accepted Answer

Chordata

Question 18

Which of the following best describes the relationship between ring species and the process of speciation?

Accepted Answer

Ring species show that speciation can occur gradually over space, with neighboring populations interbreeding but distant populations reproductively isolated.

Question 19

Which of the following is a correct sequence of events in the history of life on Earth, from oldest to most recent?

Accepted Answer

Origin of cyanobacteria → Cambrian explosion → K-Pg extinction → Evolution of humans

Phylogeny, Speciation, History of Life, and Biodiversity: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards