Question

QUESTION 2 

Climate change is a threat to the existence of many species. Which of the following limits to natural selection hinders the adaptation of species to the new climate conditions? 

• The developmental plans of plants and animals are too complex. They cannot cope with the warmer temperatures. 

• Mutations happen so frequently that beneficial alleles change before natural selection can substantially increase their frequency 

• Many species not have gene variants in their gene pool that are beneficial in higher temperatures. Climate change happens so fast that new gene variants are unlikely to arise before heat and other stresses reduce population sizes.

• Many species go naturally extinct, that has nothing to do with climate change

  
  

QUESTION 3 

In a population of fish with two alleles representing fin color, blue (B) and green (G), the original population has a frequency of 0.4 green fins, and 0.6 blue fins. If the population is in Hardy-Weinberg equilibrium, what are the frequencies of green and blue fins in the second generation? 

A 1.0 blue 

B.0.4 blue and 0.6 green 

C.0.5 green and 0.5 blue 

D.0.4 green and 0.6 blue 

QUESTION 4 

The piece of evidence that Charles Darwin was missing when he developed the theory of natural selection was that 

A. only particular traits could be acted upon by natural selection.

B. natural selection is referred to as the "survival of the fittest". 

C. the traits acted upon by natural selection were genes. 

D. traits would be inherited to an organisms offspring

QUESTION 5

The type of selection that is determined and affected by the number of individuals of a particular phenotype in the population is called: 

A. stabilizing selection B. directional selection C. frequency dependent selection D. disruptive selection

QUESTION 6 

In the example of negative frequency dependent selection, what happens to Viceroy butterflies as they become more common in the population? 

A. Predators avoid them because they mimic poisonous Monarch butterflies B. Their fitness decreases because predators likely have positive experiences when eating butterflies C. Their fitness decreases because they are competing for resources with Monarch butterflies D.None of the above

QUESTION 7 

For a population in Hardy-Weinberg equilibrium, which term represents the frequency of heterozygous individuals? 

A p² B.2pg C. q² D. None of the above

QUESTION 8 

In the Hardy-Weinberg equation, why are heterozygous individuals represented by "2pq" instead of just "pq? 

A There are two possible origins for each of the different alleles: the dominant allele originating from sperm and the recessive from the egg and vice versa. 

B. Each heterozygous individual has twice the number of alleles as each homozygous individual. 

C. The frequency of heterozygous individuals in any given population is twice that of the homozygous individuals. 

D. Both A and B are true.

QUESTION 9 

There are two color morphs of male panther chameleons, blue and orange. Blue chameleons live in trees with blue flowers and fruit while orange chameleons live in trees with orange flowers and fruit. The intermediate morph, purple, is rare since it can be easily seen by predators in trees with orange and blue flowers. This is an example of: 

A. stabilizing selection B. directional selection C. frequency-dependent selection D. disruptive selection

QUESTION 10 

After a significant amount of time of gene exchange between the two populations in this video, which of these events is most likely to occur? 

A. Rare traits will become even less frequent. B. Allelic frequencies will undergo genetic drift. C. Genetic variation will decrease. D. The populations will become genetically similar.

Answer 1

2) The answer will be many species not have gene variants in their gene pool that are beneficial in higher temperatures. Climate change happens so fast that new gene variants are unlikely to arise before heat & other stresses reduce population sizes (Third option).

Explanation: When a species has different alleles of a gene, natural selection will favor the beneficial one & other variants will be selected against. If a gene doesn't have beneficial variants for higher temperatures, natural selection will unable to work on that species as they lack beneficial allele. Further, climate change occurs more quicker than a new beneficial gene variant can arise in the population. As a result, species will not be able to adapted in the new environment. Thus, correct answer will be third option. All other options regarding limitation of natural selection are not appropriate & thus, we can ignore them.

3) The answer will be 0.4 green & 0.6 blue (Option D).

Explanation: Allele frequency remains constant over generations if a population is under Hardy-Weinberg equilibrium. As the given population is under Hardy-Weinberg equilibrium, allele frequency will same as the original population in the second generation.

5) The answer will be frequency-dependent selection (Option C).

Explanation: In stabilizing selection, heterozygotes are selected for & both homozygotes are selected against. In directional selection, one extreme phenotype is gained advantage against the other one. In disruptive selection, both homozygotes are selected for & heterozygotes are selected against. These three selections are not dependent on number of individuals. So, we can ignore options A, B & D. In frequency-dependent selection, it depends on the number of individuals of a particular phenotype. Thus, correct answer will be option C.

7) The answer will be 2pq (option B).

Explanation: Under Hardy-Weinberg equilibrium, frequency of homozygous dominant, homozygous recessive & heterozygotes is determined by p2, q2 & 2pq respectively. Thus, correct answer will be option B.

8) The answer will be the frequency of heterozygous individuals in any given population is twice that of the homozygous individuals (Option C).

Explanation: Each homozygous & heterozygous individual has same number of total alleles. So, we can ignore option B. In a Hardy-Weinberg population, the number of heterozygous individuals is twice that of homozygous individuals. This is shown in below Punnett square.

Gametes	R	B
R	RR (Homozygous)	RB (Heterozygous)
B	RB (Heterozygous)	BB (Homozygous)