Chapter 20

Question 1

What is a phylogenetic tree?

Answer 1

A phylogenetic tree is a diagram that represents the evolutionary relationships among various biological species based on similarities and differences in their physical or genetic characteristics.

Question 2

True or False: A phylogenetic tree can depict the passage of time in evolution.

Answer 2

True

Question 3

Fill in the blank: The length of the branches in a phylogenetic tree often represents _______.

Answer 3

time

Question 4

Multiple Choice: What does a node represent in a phylogenetic tree? A) A species B) A common ancestor C) A time period D) A habitat

Answer 4

B) A common ancestor

Question 5

How does the arrangement of a phylogenetic tree reflect evolutionary changes over time?

Answer 5

The arrangement shows how species diverged from common ancestors, indicating the sequence and timing of evolutionary events.

Question 6

True or False: Organisms that appear closely related on a phylogenetic tree always share a recent common ancestor.

Answer 6

False

Question 7

What is convergent evolution?

Answer 7

Convergent evolution is the process where unrelated organisms independently evolve similar traits due to adapting to similar environments.

Question 8

Fill in the blank: The similarities between organisms that are not closely related can often be attributed to __________.

Answer 8

homoplasy

Question 9

Multiple Choice: Which of the following is a reason why organisms may appear closely related despite being distantly related? A) Genetic drift B) Convergent evolution C) Natural selection D) All of the above

Answer 9

D) All of the above

Question 10

Short Answer: What role does the rate of evolution play in the interpretation of phylogenetic trees?

Answer 10

The rate of evolution can vary significantly among different lineages, leading to discrepancies in the perceived relatedness of organisms on a phylogenetic tree.

Question 11

What is the primary reason scientists distinguish between homologous and analogous traits when building phylogenetic trees?

Answer 11

To accurately represent evolutionary relationships among organisms.

Question 12

True or False: Homologous traits arise from a common ancestor, while analogous traits arise independently in different lineages.

Answer 12

True

Question 13

Fill in the blank: Homologous traits provide __________ evidence for constructing phylogenetic trees.

Answer 13

evolutionary

Question 14

Which type of trait is misleading when determining evolutionary relationships: homologous or analogous?

Answer 14

Analogous

Question 15

What is an example of a homologous trait?

Answer 15

The forelimbs of mammals, birds, and reptiles.

Question 16

What is the highest level of the taxonomic classification system?

Answer 16

Domain

Question 17

True or False: The taxonomic classification system includes only five levels.

Answer 17

False

Question 18

Fill in the blank: The second level of the taxonomic classification system is called __________.

Answer 18

Kingdom

Question 19

List the levels of the taxonomic classification system in order from highest to lowest.

Answer 19

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 20

Which level of classification comes immediately after ‘Phylum’?

Answer 20

Class

Question 21

Multiple Choice: What level of classification is ‘Canis’ in the species name ‘Canis lupus’?

Answer 21

Genus

Question 22

True or False: ‘Species’ is the most specific level of classification.

Answer 22

True

Question 23

What is the purpose of the taxonomic classification system?

Answer 23

To organize and categorize living organisms based on shared characteristics.

Question 24

Fill in the blank: The taxonomic level that groups organisms by their evolutionary history is called __________.

Answer 24

Phylogeny

Question 25

What is the lowest level of the taxonomic classification system?

Answer 25

Species

Question 26

What term describes traits that are similar due to convergent evolution, such as the body shape of dolphins and fish?

Answer 26

Analogous traits

Question 27

True or False: The similar body shape of dolphins and fish is an example of homologous traits.

Answer 27

False

Question 28

Fill in the blank: Dolphins are __________, while fish are __________.

Answer 28

mammals; aquatic animals

Question 29

What is the main reason dolphins and fish have similar body shapes?

Answer 29

Adaptation to similar aquatic environments

Question 30

Which of the following best describes homologous traits?

Answer 30

Traits that are similar due to shared ancestry

Question 31

What is the principle of maximum parsimony in phylogenetics?

Answer 31

The principle of maximum parsimony states that the simplest explanation or tree that requires the least number of evolutionary changes should be preferred.

Question 32

True or False: Maximum parsimony always provides the correct phylogenetic tree.

Answer 32

False

Question 33

Fill in the blank: Maximum parsimony is often used to infer __________ relationships among species.

Answer 33

evolutionary

Question 34

Which of the following methods is commonly associated with maximum parsimony: a) distance matrix, b) neighbor-joining, c) character-state optimization?

Answer 34

c) character-state optimization

Question 35

Short answer: What is a potential limitation of using maximum parsimony in phylogenetic analysis?

Answer 35

It can be overly simplistic and may not account for complex evolutionary scenarios such as convergent evolution.

Question 36

What are the three main theories for the evolution of eukaryotic cells?

Answer 36

The three main theories are the endosymbiotic theory, the autogenous theory, and the hybrid hypothesis.

Question 37

True or False: The endosymbiotic theory suggests that eukaryotic cells originated from a symbiotic relationship between prokaryotic cells.

Answer 37

True

Question 38

Fill in the blank: The ________ theory posits that eukaryotic cells evolved from the infolding of prokaryotic cell membranes.

Answer 38

autogenous

Question 39

Which theory combines elements of both the endosymbiotic and autogenous theories?

Answer 39

The hybrid hypothesis

Question 40

Short Answer: What is a key piece of evidence supporting the endosymbiotic theory?

Answer 40

The presence of double membranes and circular DNA in mitochondria and chloroplasts.

Question 41

What is the primary reason aphids can change color?

Answer 41

Aphids can change color primarily for camouflage and to avoid predation.

Question 42

True or False: All aphid species have the ability to change color.

Answer 42

False

Question 43

Fill in the blank: Aphids acquired color-changing abilities through ________ adaptation.

Answer 43

evolutionary

Question 44

What environmental factor is known to influence the color change in aphids?

Answer 44

Light exposure and temperature

Question 45

Which selective pressure contributes to the evolution of color change in aphids?

Answer 45

Predation by visual hunters