Exam 14: The Origin of Species

Diane Dodd raised different fruit fly populations on different food sources.She found that after about 40 generations,the evolution of reproductive isolation was under way.The mechanism of evolution responsible for this was

Organisms that possess more than two complete sets of chromosomes are said to be

The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barriers between it and the parent species describes speciation.

The Monterey pine and the Bishop's pine inhabit some of the same areas of central California.The Monterey pine releases pollen in February,while the Bishop's pine does so in April.This is an example of isolation.

Which species of wheat shown is polyploid?

Which of the following statements regarding the definition of species is false?

Two populations of organisms belong to the same biological species when they

Speciation,or the formation of new species,is

In which of the following situations would speciation be most likely to occur?

The emergence of many diverse species from a common ancestor is called

Two species that occasionally mate and produce zygotes,but which have incompatible genes that prevent the resulting embryo from developing,are separated by

Two species interbreed occasionally and produce vigorous,fertile hybrids.When the hybrids breed with each other or with either parent species,however,the offspring are feeble or sterile.These species are separated by

Which of the following types of reproductive barriers separates a pair of moth species that could interbreed except that the females' mating pheromones are not attractive to the males of the other species?

When a tetraploid flower pollinates a diploid flower of the parental species,the resulting offspring will be

One of the finest available sequences of fossils shows how horses have changed slowly and by subtle steps from small shrub- browsing ancestors to the large,grass- grazing modern horse.A large number of fossil species have been named,and it is often difficult to decide on the identity of a fossil horse because transitional forms are common.This record of evolution best fits the idea of

Most polyploid species arise from

Speciation without geographic isolation is called speciation.

Which of the following types of reproductive barriers separates two flowering plant species that could interbreed except that one has a deep flower tube and is pollinated by bumblebees,whereas the other has a short,narrow flower tube and is pollinated by honeybees?

Which of the following types of reproductive barriers separates two species of sea cucumbers,whose sperm and eggs often bump into each other but do not cross- fertilize because of incompatible proteins on their surfaces?

Sympatric speciation commonly occurs through _ in plants,but is more likely to occur through _ in animals.