Question 1

Which of the following best describes the main inference Darwin made from his observations of finches on the Galapagos Islands?

Accepted Answer

Finches on the Galapagos originated from South America and became modified on each island due to local conditions.

Question 2

Which of the following is NOT a necessary condition for natural selection to occur, according to Darwin's mechanism?

Accepted Answer

All individuals survive and reproduce equally.

Question 3

A population of fish is exposed to a new predator. Over several generations, the frequency of a recessive allele decreases, but never disappears. Which evolutionary principle explains why the recessive allele persists?

Accepted Answer

The recessive allele is hidden in heterozygotes and thus not always exposed to selection.

Question 4

In a population under balancing selection due to heterozygote advantage, the frequency of the recessive allele ($$q) $$can be calculated using which formula?

Accepted Answer

$$q = \frac{s}{s+t}$$

Question 5

Which of the following is an example of intrinsic reproductive isolation?

Accepted Answer

Two species of frogs breed at different times of the year.

Question 6

Which scenario best illustrates sympatric speciation?

Accepted Answer

Fruit flies in the same orchard become reproductively isolated due to a shift in host plant preference and breeding time.

Question 7

Which of the following statements about the biological species concept is correct?

Accepted Answer

It requires that members of a species are reproductively isolated from other groups.

Question 8

Which of the following best describes a synapomorphy in cladistics?

Accepted Answer

A shared, derived characteristic inherited from a common ancestor.

Question 9

Which of the following is an example of homoplasy?

Accepted Answer

The presence of wings in bats and birds due to convergent evolution.

Question 10

A marine fish is placed in a tank with water of much lower salinity than its natural environment. Which physiological response is most likely to occur?

Accepted Answer

It will passively gain water and lose salt.

Question 11

Which of the following best explains why sharks and rays can maintain higher concentrations of urea in their bodies compared to bony fish?

Accepted Answer

They use rectal glands to excrete excess salts and retain urea for osmotic balance.

Question 12

Which of the following is a key difference between osmoregulators and osmoconformers?

Accepted Answer

Osmoregulators maintain a constant internal osmolarity, while osmoconformers' osmolarity changes with the environment.

Question 13

A freshwater amphibian is moved to a slightly saline pond. Which of the following is the most likely physiological challenge it will face?

Accepted Answer

Passive water loss and salt gain through its permeable skin.

Question 14

Which nitrogenous waste product is most advantageous for terrestrial reptiles and why?

Accepted Answer

Uric acid, because it is low in toxicity and conserves water by being excreted as a solid.

Question 15

Which of the following best describes the function of the loop of Henle in the mammalian nephron?

Accepted Answer

It reabsorbs water and concentrates urine by creating a gradient in the medulla.

Question 16

A migratory fish moves from freshwater to seawater. Which regulatory adjustment is most critical for its survival?

Accepted Answer

Increasing active salt excretion through the gills.

Question 17

Which of the following is the correct order of taxonomic ranks from most inclusive to least inclusive?

Accepted Answer

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

Question 18

Which of the following best illustrates the principle of parsimony in cladistics?

Accepted Answer

Choosing the evolutionary tree that requires the fewest evolutionary changes.

Question 19

A researcher finds two populations of frogs that look identical but have different mating calls and do not interbreed in the wild. According to the biological species concept, these populations are:

Accepted Answer

Different species because they are reproductively isolated.

Question 20

Which of the following best explains why marine birds and reptiles have specialized salt glands?

Accepted Answer

They need to excrete excess salt that cannot be removed by the kidneys.

Evolution, Speciation, and Osmoregulation: Key Concepts in Biology

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