Question 1

Which of the following best describes anagenesis in evolutionary genetics?

Accepted Answer

Evolutionary change within a single lineage over time

Question 2

A population of frogs shows high levels of genetic variation in both protein and DNA sequence. Why is this variation important for evolution?

Accepted Answer

Genetic variation is necessary for evolution to occur within populations

Question 3

Which reproductive isolating mechanism acts before the formation of a zygote and can prevent two species from interbreeding?

Accepted Answer

Prezygotic isolating mechanism

Question 4

Darwin’s finches on the Galápagos Islands are an example of which type of speciation?

Accepted Answer

Allopatric speciation

Question 5

Which of the following is a postzygotic reproductive isolating mechanism?

Accepted Answer

Hybrid sterility

Question 6

A plant species arises through the formation of a polyploid. What type of speciation is this most likely to represent?

Accepted Answer

Sympatric speciation

Question 7

Which concept defines a species as a group of organisms capable of interbreeding and producing viable, fertile offspring?

Accepted Answer

Biological species concept

Question 8

In a phylogenetic tree, what does a node (branch point) represent?

Accepted Answer

The divergence of one species into two or more species

Question 9

Which of the following is true about homologous structures?

Accepted Answer

They are similarities due to shared ancestry

Question 10

A population of birds is split by a newly formed river, preventing gene flow. Over time, the two groups evolve into separate species. Which equation best represents the probability of gene flow between the two populations after the barrier forms?

Accepted Answer

$$P_{gene\ flow} = 0$$

Question 11

Which approach to constructing phylogenetic trees seeks the tree with the minimum number of evolutionary changes?

Accepted Answer

Parsimony approach

Question 12

If two species of frogs breed at different times of the year, which type of prezygotic isolating mechanism is this?

Accepted Answer

Temporal isolation

Question 13

Which of the following statements about molecular variation is correct?

Accepted Answer

Molecular methods can be used with all organisms

Question 14

A gene tree is constructed using DNA sequences from multiple species. What does the root of the tree represent?

Accepted Answer

The most recent common ancestor of all genes in the tree

Question 15

Which of the following is an example of horizontal gene transfer?

Accepted Answer

Exchange of genetic material between different species

Question 16

If $$F_1$$ hybrids between two species are viable and fertile, but $$F_2$$ hybrids are inviable or sterile, which postzygotic isolating mechanism is this?

Accepted Answer

Hybrid breakdown

Question 17

Which of the following best explains why polyploidy is a major form of speciation in plants but rare in animals?

Accepted Answer

Polyploidy leads to immediate reproductive isolation in plants

Question 18

Which equation would you use to calculate the genetic distance between two DNA sequences for constructing a phylogenetic tree?

Accepted Answer

$$D = \frac{S}{N}$$, where $$S is $$the number of sequence differences and $$N is $$the total number of sites compared

Question 19

Which of the following is NOT a prezygotic isolating mechanism?

Accepted Answer

Hybrid inviability

Question 20

A monophyletic group (clade) in a phylogenetic tree includes:

Accepted Answer

All descendants of the group's most recent common ancestor

Study Notes: Evolutionary Genetics (Chapter 26)

Guida di studio - Domande di pratica

Study guide - Flashcard