Unit 2 Exam

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

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

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

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

A  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.

B  is called the theory of phyletic gradualism.

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

D  one possible explanation of speciation accepted by biologists today.

A  parallel evolution.

B  microevolution.

C  punctuated equilibrium.

D  gradualism.

A  environments change slowly.

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

C  natural selection is a powerful process.

D  new mutations are usually maladaptive.

A  sexual selection between two different species

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

C  gene flow among members of the same species.

D  genetic drift within populations.

A  generalization.

B  parallel evolution.

C  homology.

D  adaptive radiation.

A  allopatric speciation.

B  extinction

C  migration

D  sympatric speciation.

A  large scale evolutionary change such as speciation

B  small scale evolutionary changes within a single generation

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

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

A  the death of individuals in a group.

B  the formation of new species.

C  the extinction of a species.

D  evolutionary change within a species.

A  the change from one species to another in one generation

B  the appearance of new species

C  any type of genetic mutation

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

A  All of these forces may disrupt equilibrium.

B  gene flow

C  mutation

D  genetic drift

A  the differential reproductive success of individuals

B  the production of new genetic material

C  the exchange of genes between populations

D  the chance loss of alleles in a population

A  maladaptive changes in gene frequencies.

B  equilibrium in genetic frequencies.

C  adaptive changes in gene frequencies.

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

A  medium-sized populations.

B  large populations.

C  small populations.

D  populations out of equilibrium.

A  recombination

B  mutation

C  genetic drift

D  migration

A  all of these are important in shaping continuously varying traits

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

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

D  are affected by genes at many loci.

A  migration

B  genetic drift

C  mutation

D  natural selection

A  Mutations can be hidden in the heterozygous genotype.

B  New variation is slowly added by mutation.

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

D  There is no blending during sexual reproduction.

A  the sex cells or eggs and sperm.

B  do not differ between male and female animals.

C  the somatic cells of the body.

D  were discovered by Darwin.

A  genetic drift

B  mutation

C  allele

D  gene

A  Chromosomes come in pairs.

B  These are all true about choromsomes

C  Hereditary material is contained in the chromosomes.

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

A  dominant trait

B  non-genetic trait

C  mendelian trait

D  polygenic trait

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

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

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

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

A  changed because equilibrium existed in the population

B  never changed because of stasis

C  never changed because of high juvenile mortality

D  changed over time because of environmental change

A  averaging selection

B  disruptive selection

C  directional selection

D  stabilizing selection

A  almost always occur by chance alone.

B  allow organisms to evolve more rapidly.

C  cannot be passed from parent to offspring.

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

A  there is no competition.

B  evolutionary change would proceed in a nonadaptive direction.

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

D  traits are not inherited by offspring.

A  variation in fitness.

B  the inheritance of variation.

C  the struggle for existance.

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

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

B  all of these are essential elements of natural selection.

C  individuals within a population vary.

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