Key Concepts Quiz
This activity contains 11 questions.
Macroevolution can be defined as _____.
a change in allele frequencies in a population
a disruption of the Hardy-Weinberg equilibrium within a population
the occurrence of genetic drift in a large population
the appearance and extinction of species and the formation of major new branches on the tree of life
The _____ species concept is the most applicable to classifying species from the fossil record?
When a horse and a donkey mate, they produce infertile hybrids called mules. According to the _____ species concept, horses and donkeys are _____.
biological … the same species
biological … different species
ecological ... the same species
ecological … different species
Two species of clams inhabit the same marine habitat along the Atlantic coast. One releases gametes into the water in early spring, and the second species releases gametes into the water in late summer. Which type of reproductive barrier is at work between these species?
reduced hybrid viability
Two rodent populations become separated when a large canyon develops in a previously unbroken forest. When is allopatric speciation between the two populations complete?
As soon as gene flow is reduced between the two populations, they are properly considered separate species.
When gene flow stops between the two populations (the species is incapable of crossing the canyon), allopatric speciation is complete and you have two separate species.
When the two populations evolve to develop recognizably different physical traits, you would definitely have two separate biological species.
When the two populations evolve to be different enough so that they are incapable of interbreeding successfully when given the opportunity to do so under natural conditions, allopatric speciation is complete.
Which population would be most likely to undergo relatively rapid allopatric speciation?
A population of flowering plants lives along the shore of a pond about one kilometer from the nearest neighboring population. Hummingbirds regularly fly back and forth across this distance and transport pollen between the two populations.
A group of birds develops a unique set of mating preferences so that they are unlikely to mate with other birds of the same species in the same geographic area.
A group of wild horses is transported from Wyoming to a small desert island, previously without horses, off the coast of California. No additional horses reach the island thereafter.
A population of snakes becomes separated from other populations on a very large island that is formed by rising sea levels. Occasionally, a snake or two swims from the mainland to the island or from the island to the mainland.
Which type of organism is most likely to undergo sympatric speciation by polyploidy?
animals, particularly those with highly selective females that select mates based on exaggerated traits
animal species with poor dispersal abilities whose populations exist in widely separated, small patches of habitat
plant species that are capable of self-pollination and some degree of asexual reproduction
plant species that are incapable of asexual reproduction and do not self-pollinate
A diploid cell in a plant undergoes chromosome duplication but fails to divide properly, initiating a tetraploid (4
) branch. This branch produces a 4
flower. What can happen next?
The tetraploid (4
) flower produces 2
gametes and may then be able to self-pollinate to produce fertile 4
flower produces 2
gametes, which then cross-fertilize with gametes from the original diploid parent species to produce fertile offspring.
flower produces 1
(haploid) gametes, which then cross-fertilize with gametes from the original diploid parent species to produce fertile offspring.
flower produces 4
(tetraploid) gametes, which then self-fertilize to produce fertile offspring.
The two species of finches studied by the Grants on Daphne Major are known to hybridize. What is their status?
They hybridize occasionally when the behavioral barrier separating the species fails. The fitness of hybrids fluctuates depending on the weather: Some succeed, but most do not. The result over the long term is a stable hybrid zone.
They hybridize frequently because the mechanical reproductive barrier separating them is weak.
They hybridize frequently, but the hybrid individuals always die due to poor foraging abilities. Therefore, given enough time, the reproductive barrier will be reinforced and hybridization will cease.
They hybridize infrequently despite the temporal isolation that normally prevents interbreeding.
In which of the following situations is adaptive radiation
likely to occur?
The dominant organisms in an area become extinct.
A new island chain forms far from shore and is reached by a few groups of long-distance colonists.
A species has flexible morphological structures that lend themselves to specialization.
A species with inflexible morphological traits finds itself in a species-rich, highly competitive environment.
What is shown in the figure below?
The Clear Answers feature requires scripting to function. Your browser either does not support scripting or you have turned scripting off. So, the Clear Answers feature will not work. Note that you do not need to use the Clear Answers feature in order to use this site. You can change your answers for each question individually.
Copyright © 1995 - 2011
. All rights reserved.
[Return to the Top of this Page]