Question 1

Which of the following best describes a 'clade' in the context of cladistics?

Accepted Answer

A group that includes an ancestral species and all of its descendants.

Question 2

In binomial nomenclature, which of the following is the correct way to write the scientific name for humans?

Accepted Answer

$Homo\ sapiens$

Question 3

A phylogenetic tree shows that glass lizards and snakes evolved from different legged ancestors, yet both lack limbs. What evolutionary concept does this illustrate?

Accepted Answer

Convergent evolution

Question 4

Which of the following statements about phylogenetic trees is TRUE?

Accepted Answer

Branch points represent the most recent common ancestor of the descendant taxa.

Question 5

A scientist is comparing DNA sequences between two species. She finds that the number of nucleotide substitutions per site is $d = 0.05$. If the molecular clock rate is $r = 1 	imes 10^{-8}$ substitutions per site per year, estimate the divergence time $T$ between the two species using the formula $T = \frac{d}{2r}$. What is $T$?

Accepted Answer

$2.5 	imes 10^{6}$ years

Question 6

Which of the following is an example of a shared derived character (synapomorphy) for mammals?

Accepted Answer

Hair

Question 7

Why might two unrelated species, such as the Australian 'mole' and the African golden mole, appear similar in external anatomy?

Accepted Answer

They have undergone convergent evolution due to similar environmental pressures.

Question 8

Which of the following best describes a paraphyletic group?

Accepted Answer

A group that includes an ancestral species and some, but not all, of its descendants.

Question 9

A researcher is mapping the presence of feathers onto a phylogenetic tree of reptiles and birds. Feathers are found only in birds. On the tree, how should feathers be classified?

Accepted Answer

A derived character

Question 10

Which of the following is a limitation of using morphological data alone to construct phylogenetic trees?

Accepted Answer

Convergent evolution can result in similar traits in unrelated groups, leading to incorrect groupings.

Question 11

Which of the following best explains why molecular clocks are sometimes inaccurate?

Accepted Answer

Some genes evolve at different rates in different lineages.

Question 12

Which of the following is the correct hierarchical order in biological classification from most inclusive to least inclusive?

Accepted Answer

Domain, kingdom, phylum, class, order, family, genus, species

Question 13

A scientist is using the principle of maximum parsimony to construct a phylogenetic tree. What is she trying to achieve?

Accepted Answer

She is seeking the tree that requires the fewest evolutionary changes.

Question 14

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

Accepted Answer

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

Question 15

Which of the following is a reason why DNA sequence data is often more reliable than morphological data for constructing phylogenies?

Accepted Answer

DNA sequences are less likely to be affected by convergent evolution than morphological traits.

Question 16

If a phylogenetic tree shows a polytomy, what does this indicate?

Accepted Answer

There is an unresolved pattern of divergence among three or more lineages.

Question 17

Which of the following is an example of a homologous structure?

Accepted Answer

The forelimbs of whales and bats

Question 18

A scientist is comparing the number of nucleotide differences between two species. She finds 120 differences in a gene that is 1,000 nucleotides long. What is the proportion of differences ($p$) between the two species?

Accepted Answer

$p = 0.12$

Question 19

Which of the following is a key difference between homology and analogy?

Accepted Answer

Homology is similarity due to shared ancestry, while analogy is similarity due to convergent evolution.

General Biology Study Notes: Phylogeny, Classification, and Molecular Evolution

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