Unit 2 Exam

A  when there is extensive gene flow within a single species.

B  males and females don’t like each other very much and so prefer not to mate.

C  when interbreeding between two different species results in less successful hybrid offspring.

D  because there is over-population and species survival depends on a new species evolving.

A  is not the only pattern of speciation observed in the natural world.

B  one possible explanation of speciation accepted by biologists today, is not the only pattern of speciation observed in the natural world and is called the theory of phyletic gradualism.

C  one possible explanation of speciation accepted by biologists today.

D  is called the theory of phyletic gradualism.

A  parallel evolution.

B  punctuated equilibrium.

C  microevolution.

D  gradualism.

A  gene flow between individuals within the population keeps them similar to each other.

B  natural selection is a powerful process.

C  new mutations are usually maladaptive.

D  environments change slowly.

A  genetic drift within populations.

B  sexual selection between two different species

C  they way natural selection favors particular traits suited to a specific ecological niche.

D  gene flow among members of the same species.

A  generalization.

B  adaptive radiation.

C  parallel evolution.

D  homology.

A  extinction

B  allopatric speciation.

C  migration

D  sympatric speciation.

A  large scale evolutionary change such as speciation

B  how the evolution of one species affects the evolution of another species

C  the relationship between humans and other animals in their ecological niche

D  small scale evolutionary changes within a single generation

A  the death of individuals in a group.

B  the extinction of a species.

C  evolutionary change within a species.

D  the formation of new species.

A  the change from one species to another in one generation

B  the appearance of new species

C  the change in allele frequencies from one generation to the next

D  any type of genetic mutation

A  mutation

B  gene flow

C  genetic drift

D  All of these forces may disrupt equilibrium.

A  the production of new genetic material

B  the chance loss of alleles in a population

C  the exchange of genes between populations

D  the differential reproductive success of individuals

A  equilibrium in genetic frequencies.

B  adaptive changes in gene frequencies.

C  maladaptive changes in gene frequencies.

D  changes in gene frequencies that are random with respect to adaptation.

A  medium-sized populations.

B  populations out of equilibrium.

C  large populations.

D  small populations.

A  genetic drift

B  recombination

C  migration

D  mutation

A  are shaped by many genes, each with only a small effect on the phenotype.

B  can be greatly impacted by the environment during an individual’s growth and development.

C  all of these are important in shaping continuously varying traits

D  are affected by genes at many loci.

A  natural selection

B  mutation

C  genetic drift

D  migration

A  All of these are ways that genetic variation remains within a population.

B  New variation is slowly added by mutation.

C  There is no blending during sexual reproduction.

D  Mutations can be hidden in the heterozygous genotype.

A  the somatic cells of the body.

B  the sex cells or eggs and sperm.

C  do not differ between male and female animals.

D  were discovered by Darwin.

A  allele

B  genetic drift

C  mutation

D  gene

A  Hereditary material is contained in the chromosomes.

B  One chromosome from each homologous pair is passed on to gametic cells during meiosis.

C  Chromosomes come in pairs.

D  These are all true about choromsomes

A  polygenic trait

B  dominant trait

C  non-genetic trait

D  mendelian trait

A  the survivors of the drought had a larger average beak size

B  The Grants found all these things as part of their study.

C  beak size is inherited so the next generation had a larger average beak size

D  a large number of the birds had died as a result of the drought

A  changed over time because of environmental change

B  never changed because of stasis

C  changed because equilibrium existed in the population

D  never changed because of high juvenile mortality

A  directional selection

B  averaging selection

C  stabilizing selection

D  disruptive selection

A  allow organisms to evolve more rapidly.

B  cannot be passed from parent to offspring.

C  are components of organisms that enable them to survive and reproduce.

D  almost always occur by chance alone.

A  there is no competition.

B  there are no differences in the traits to be favored and affect survival and reproducation.

C  traits are not inherited by offspring.

D  evolutionary change would proceed in a nonadaptive direction.

A  Natural selection is based on all three of these answers.

B  variation in fitness.

C  the inheritance of variation.

D  the struggle for existance.

A  all of these are essential elements of natural selection.

B  while organisms within a population reproduce rapidly, resources are limited.

C  individuals with useful adaptations will be more likely to survive and reproduce.

D  individuals within a population vary.