Question

24. Which of the following species concepts is defined by populations of interbreeding individuals that are reproductively isolated from other populations? 

A. phylogenetic B. ecological C. biological D. morphological

On the Bahamian Island of Andros, mosquitofish populations live in now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish with a body shape that allows them to swim in short, fast bursts. Other predator-poor ponds have mosquitofish with a body shape that allows them to swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences and will only mate with male mosquitofish typical of their native pond. 

29. Which two of the following have operated to increase divergence between mosquitofish populations on Andros? 

,1. gene flow between ponds 2. bottleneck effect 3. sexual selection 4. founder effect 5. natural selection

 A. 1 and 3 B. 2 and 3 C. 2 and 4 D. 3 and 4 E. 3 and 5

34. Thee origin of a new plant species by hybridization between two closely related but distinct species followed by genome duplication is an example of 

A. sympatric speciation. B. autopolyploidy. c. allopolyploidy D. A and B. E. A and C.

36. Speciation

 A. occurs at such a slow pace the emergence of new species has never been observed.

 B. occurs only by the gradual accumulation of genetic change over vast expanses of time.

 C. always begins with the geographic isolation of a small, founder population.

 D, and microevolution are synonymous terms. E. can involve changes to a single gene.

Answer 1

Question 24:

Answer: Species concept defines what a species is. They various types of species concepts

Phylogentic species concept defines species as a population that have unique evolutionary history. They are all descended from common ancestor.

Elcological species concept defines species as group of organism that are adapted to a niche in the environment.

Morphological species concept defines species based on the difference in the morphological characters. Hence, option A, B and D are incorrect.

Biological species concept defines species as a group of individual that can interbreed and reproductively isolated from other populations. Hence, option C is the correct answer.

Question 29

Answer: Natural selection and sexual selection played major role in increasing the divergence between mosquitofish populations in Andros. Natural selection favours the growth of mosquitofish with body shape that allows to them to swin in short, fast brusts in predator-rich pond becuase they need to get protected from predators whereas, in ponds where predators are poor, mosquitofish with body shape that allow them to swim continuously for long time predominates. Sexual selection is a type of natural selection and involves intrasexual and intersexual selection. This means that reproductive success of some individuals is better than other individuals of same population. Hence, female mosquitofish exhibit unique breeding preference to male fishes of their own pond. The correct answer is option E.