Chapter 18 Reading Quiz

Which are two primary sources of genetic variation? mutations and sexual reproduction isolation and sexual reproduction sexual reproduction and asexual reproduction migration and sexual reproduction

mutations and sexual reproduction

Which scientific concept did Charles Darwin and Alfred Wallace independently discover?

natural selection

adaptive radiation

speciation when one species radiates out to form several other species, many adaptations evolve from a single point of origin

Gametic isolation

sperm of one may not fertilize the other

Reconnection

the continuous interaction between species

Reduction of gene flow results in what?

the formation of a new species

Gene flow

the transfer of alleles between populations, holds populations together

behavioral isolation

type of reproductive isolation that occurs when a specific behavior or lack of one prevents reproduction from taking place (courtship rituals)

Which is an example of an adaptation? The better nutrition of a human helps her grow taller. The webbed feet of a duck help it swim. The urban location of a raccoon helps it find food. The large leaves of a desert plant require more water.

webbed feet of a duck to help it swim

hybrid zone

area where two closely related species continue to interact and reproduce, forming hybrids

variation

genetic differences among individuals in a population

Which situation would most likely lead to allopatric speciation? A flood causes the formation of a new lake. A storm causes several large trees to fall down. A mutation causes a new trait to develop. An injury causes an organism to seek out a new food source.

A flood causes the formation of a new lake

Which best describes what happens when an antibiotic is applied to a population of bacteria? The bacteria develops resistance to the antibiotic in direct response to its application. The bacteria's genetic material mutates in response to the antibiotic, resulting in resistance. A gene for resistance, already present in the population, decreases in frequency. A gene for resistance, already present in the population, increases in frequency.

A gene for resistance, already present in the population, increases in frequency.

Which of the processes described is divergent evolution? a. Groups of organisms evolve in different directions from a common point. b. A new species develops rapidly when an event cuts off a portion of a population. c. Groups of organisms independently evolve to similar forms. d. A species evolves when a few members move to a new geographical area.

Groups of organisms evolve in different directions from a common point

Which situation is most likely an example of convergent evolution? a. Some fish that live in total darkness have eyes. b. Hawks and other birds have feathers. c. Worms and snakes both move without legs. d. Flowers that look very different have the same reproductive organs.

Hawks and other birds have feathers

What is unique about speciation due to adaptive radiation? It leads to multiple species forming from one parent species. It only occurs on or around island archipelagos. It requires a population to disperse from its parent species. It is a special kind of sympatric speciation.

It leads to multiple species forming from one parent species.

Mechanical isolation

Morphological differences prevent fertilization, doesn't fit

Which of the following statements is false? Gradual speciation and punctuated equilibrium both result in the divergence of species. Punctuated equilibrium is most likely to occur in a large population in a stable environment. In the punctuated equilibrium model, gradualism is not excluded. In the gradual speciation model, traits change incrementally.

Punctuated equilibrium is most likely to occur in a large population in a stable environment.

Which of these statements about a natural principle that points to the inevitability of natural selection is false? a. Most characteristics of organisms are inherited. b. Offspring vary among each other in regard to their characteristics. c. Some generations of offspring do not need to compete for resources. d. Certain traits will be better represented in the next generation.

Some generations of offspring do not need to compete for resources

Which statement best describes the relationship between the theory of evolution and the origin of life? The theory includes an explanation of life's origins. The theory cannot explain the origin of life. The theory does not try to explain the origin of life. The theory does not contribute understanding to pre-life processes.

The theory does not try to explain the origin of life

Which statement about postzygotic barriers is false? They occur after fertilization. They include hybrids that are sterile. They include hybrid organisms that don't survive the embryonic stage. They include reproductive organ incompatibility.

They include reproductive organ incompatibility.

Which situation is an example of a prezygotic barrier? Two species of fish produce sterile offspring. Two species of flowers attract different pollinators. Two species of insects mate, but the zygote does not survive. Two species of lizards mate, but the offspring dies before reproducing.

Two species of flowers attract different pollinators.

Which statement best describes the relationship between genetic variation and speciation? Without genetic variation, speciation would occur more slowly. Without genetic variation, speciation would not be possible. Genetic variation influences sympatric speciation, but not allopatric speciation. There is no relationship between genetic variation and any form of speciation.

Without genetic variation, speciation would not be possible.

Which is the best definition of species? a group of individual organisms with significant genetic similarities a group of individual organisms with significant genetic similarities that share external and internal characteristics a group of individual organisms that interbreed a group of individual organisms that interbreed and produce viable, fertile offspring

a group of individual organisms that interbreed and produce viable, fertile offspring

Which is the best definition of adaptation? a. a trait or behavior that aids an organism's survival and reproduction b. a heritable trait or behavior that aids an organism's survival and reproduction c. a trait or behavior that aids a population's survival and reproduction d. a heritable trait or behavior that aids a population's survival and reproduction

a heritable trait or behavior that aids an organism's survival and reproduction

dispersal

allopatric speciation that occurs when a few members of a species move to a new geographical area

vicariance

allopatric speciation that occurs when something in the environment separates organisms of the same species into separate groups

Polyploidy

condition in which a cell or organism has an extra set, or sets, of chromosomes (leads to reproductive isolation)

aneuploidy

condition of a cell having an extra chromosome or missing a chromosome for its species, chromosomes don't split like they are supposed to

reinforcement

continued speciation divergence between two related species due to low fitness of hybrids between them, the production of less fit hybrids over time indicating an even further divide of the two species

temporal isolation

differences in breeding schedules that can act as a form of prezygotic barrier leading to reproductive isolation

theory of evolution

explains how populations change over time and how life diversifies the origin of species

Zygote

fertilized egg

speciation

formation of a new species

polyploidy

gametes with extra chromosomes

Which is least likely to be a factor that increases the probability of speciation by adaptive radiation? There are vacant ecological niches nearby. Genetic drift in a population increases. There are isolated regions with suitable habitats. There are few competitor species.

genetic drift in a population increases

species

group of populations that interbreed and produce fertile, viable offspring

Five types of prezygotic barriers

habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, gametic isolation

adaptation

heritable trait or behavior in an organism that aids in its survival and reproduction in its present environment

Which of the following are two examples of vestigial structures? gills in fish and parts of the throat in humans butterfly wings and dragonfly wings hind leg bones in whales and leaves on some cacti shark fins and dolphin fins

hind leg bones in whales and leaves on some cacti

punctuated equilibrium

model for rapid speciation that can occur when an event causes a small portion of a population to be cut off from the rest of the population, a new species undergoes changes quickly from the parent species, and then remains largely unchanged for long periods of time afterward

gradual speciation model

model that shows how species diverge gradually over time in small steps

acquired characteristics

modifications caused by an individual's environment that can be inherited by its offspring

hybrid

offspring of two closely related individuals, not of the same species

Which component of speciation would be least likely to be a part of punctuated equilibrium? a division in populations a change in environmental conditions ongoing gene flow a number of mutations occuring at once

ongoing gene flow

What are homologous structures? a. physical structures that have no apparent function b. parallel structures in diverse organisms c. physical structures that are used only occasionally d. similar structures in diverse organisms

parallel structures in diverse organisms

homologous structures

parallel structures in diverse organisms that have a common ancestor

vestigial structure

physical structure present in an organism but that has no apparent function and appears to be from a functional structure in a distant ancestor

allopolyploid

polyploidy formed between two related, but separate species gametes from two different species combine

autopolyploid

polyploidy formed within a single species, polyploid individual will have two or more complete sets of chromosomes from its own species (cell does not separate)

gametic barrier

prezygotic barrier occurring when closely related individuals of different species mate, but differences in their gamete cells (eggs and sperm) prevent fertilization from taking place

divergent evolution

process by which groups of organisms evolve in diverse directions from a common point

convergent evolution

process by which groups of organisms independently evolve to similar forms

. In a hybrid zone, in addition to interacting, what else do two closely related species do? compete reproduce transition fuse

reproduce

natural selection

reproduction of individuals with favorable genetic traits that survive environmental change because of those traits, leading to evolutionary change

.What do scientists focus on to distinguish between species? ecological niches morphological differences reproductive barriers genetic changes

reproductive barriers

Which situation means reinforcement is more likely to occur in the hybrid zone? The hybrid offspring are more fit than the parent species. Reproductive barriers weaken. The hybrid offspring are about as fit as the parent species. Reproductive barriers strengthen.

reproductive barriers strengthen

postzygotic barrier

reproductive isolation mechanism that occurs after zygote formation

prezygotic barrier

reproductive isolation mechanism that occurs before zygote formation, mechanism that blocks reproduction from taking place

habitat isolation

reproductive isolation resulting when populations of a species move or are moved to a new habitat, taking up residence in a place that no longer overlaps with the other populations of the same species

reproductive isolation

situation that occurs when a species is reproductively independent from other species; this may be brought about by behavior, location, or reproductive barriers he existence of biological factors (barriers) that impede members of two species from interbreeding and producing viable, fertile offspring

What is the main difference between an autopolyploid individual and a allopolyploid individual? number of extra chromosomes functionality of extra chromosomes source of extra chromosomes number of mutations in the extra chromosomes

source of extra chromosomes

sympatric speciation

speciation that occurs in the same geographic space

allopatric speciation

speciation that occurs via geographic separation, gene flow is interrupted when a population is decided into geographically isolated subpopulations