bio chp 24 hw

hybrid inviability

An egg cell is successfully fertilized by the sperm of a different species, but the resulting zygote fails to develop past the early embryonic stages.

hybrid breakdown

An interspecies hybrid is able to produce gametes and reproduce with other hybrids, but subsequent generations harbor detrimental genetic abnormalities.

hybrid sterility

An interspecies hybrid zygote develops to maturity, but it is incapable of producing viable gametes.

______ isolation occurs when differences in mating behavior prevent members of two different species from interbreeding.

Behavioral

gametic isolation

Gametes are exchanged, but the egg is not successfully fertilized to produce a zygote.

Which of the following is not a mechanism of prezygotic isolation?

Hybrid breakdown

Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?

Hybrid inviability

Which of the following is an example of behavioral isolation?

Inability of different species of meadowlarks to recognize each other as potential mates due to differences in their songs

__ describes evolutionary changes that create new species and groups that include many new species.

Macroevolution

How does hybrid sterility prevent successful interbreeding among members of different species?

Mating results in production of a hybrid zygote; however, the hybrid is sterile at maturity.

Which of the following types of prezygotic isolating mechanisms are described correctly?

Mechanical isolation: Mating is attempted, but anatomical differences prevent the successful exchange of gametes. Habitat isolation: Members of two different species never come into contact with one another because they live in different places. Gametic isolation: Gametes are exchanged, but the egg is not successfully fertilized to produce a zygote.

How does the biological species concept define a species?

Members of a species are able to interbreed in nature and are reproductively isolated from members of other species.

behavioral isolation

Members of different species differ in their mating rituals.

geographic isolation

Members of two different species never come into contact with one another because they live in different places.

Which of the following statements regarding the prevalence of polyploidy is TRUE?

Plants tend to be more tolerant of changes in chromosome number than animals.

Which of the following statements are TRUE regarding the conditions necessary for allopatric speciation?

Populations cannot be sympatric (living in the same location). Interbreeding among populations must be eliminated or greatly limited.

______ isolating mechanisms block the development of a viable and fertile individual after fertilization has taken place.

Postzygotic

What type of reproductive isolation mechanisms produces infertile hybrids or prevent hybrid offspring from developing?

Postzygotic isolating mechanisms

______ isolating mechanisms prevent the formation of a zygote.

Prezygotic

Select the two main types of reproductive isolating mechanisms.

Prezygotic isolating mechanisms Postzygotic isolating mechanisms

Which of the following statements is MOST accurate regarding the relative frequencies of prezygotic and postzygotic isolating mechanisms?

Prezygotic isolating mechanisms tend to be MORE common than postzygotic mechanisms

What is sympatric speciation?

Speciation that occurs when populations occurring in the same area diverge into two species when there are no physical barriers to interbreeding

temporal isolation

Species reproduce at different times of the day or year

mechanical isolation

Structural differences between species prevent mating.

What is macroevolution?

The evolutionary changes that result in the formation of new species

Which of the following is an example of temporal isolation as a prezygotic isolating mechanism?

Two species of plants live within the same area but one flowers (reproduces) in the fall and the other in the spring.

Two major reasons have been proposed to explain why organisms assemble into different species: 1. Speciation may occur due to abrupt genetic events, which can cause reproductive isolation, or 2. Speciation may arise as a consequence of

adaptation to different ecological niches

Speciation that occurs when populations are physically separated from one another is __ speciation, whereas __ speciation occurs when populations co-occur.

allopatric sympatric

A(n) ______ organism contains at least one set of chromosomes from two or more different species.

alloploid

An organism that contains at least one set of chromosomes from two or more different species is:

alloploid

An increase in the number of chromosome sets in a given species, resulting from nondisjunction, is known as:

autopolyploidy

When a complete nondisjunction of chromosomes results in an increase in the number of chromosome sets in a given species, the result is a type of polyploidy called ______.

autopolyploidy

Which of the following are difficult to categorize into distinct species?

bacteria

A vast number of species have yet to be classified. This is especially true among __, which are difficult to categorize into distinct species.

bacteria and archaea

The inability of the female of one species of meadowlark to recognize a male of a different species as a potential mate because of the differences in their songs is an example of __ , prezygotic isolation?

behavioral

Two different species are prevented from interbreeding due to differences in mating behavior. This is example of:

behavioral isolation

The __ species concept defines a species as a group of individuals that is able to interbreed, producing viable and fertile offspring.

biological

Which of the following are examples of morphological traits that can be used to classify organisms as the same species?

cell anatomy sensory structures body shape

Consider a population of sexually-reproducing organisms that splits into two or more species. This phenomenon is referred to as:

cladogenesis

Which of the following are examples of circumstances that could potentially lead to sympatric speciation?

differences in male behavior that influence female mate choice differences in toleration of contaminants in soil, water, or air interspecies mating, resulting in polyploid hybrid offspring

Of the following, which are examples of sympatric speciation?

divergence of apple maggot flies into separate subspecies depending on whether they prefer apple or hawthorn as host plants aggregation of cichlids into distinct populations based on female choice of male coloration reproductive isolation of Galeopsis tetrahit because it is an allopolyploid as a result of a hybridization event

What characteristics are often used to identify different species?

ecological factors molecular features ability to interbreed morphological traits evolutionary relationships

True or false: Populations must be completely geographically isolated in order for allopatric speciation to occur.

false

True or false: Prezygotic isolating mechanisms are less common than postzygotic isolating mechanisms.

false

Speciation most commonly occurs when

genetic changes in a particular group deviate from its parent population.

Members of different species that are prevented from coming into contact with one another, often because of some kind of physical barrier, are experiencing __ isolation.

geographic

Lions (Panthera leo) are native to Africa and tigers (Panthera tigris) are native to Asia, so they never have an opportunity to interbreed. This is an example of __ reproductive isolation.

habitat

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?

habitat isolation

Two species of the garter snake in the genus Thamnophis are found in the same geographic region. These species are not likely to meet and attempt to reproduce because one lives mainly in the water, whereas the other species spends most of its time on land. This is known as:

habitat isolation

A cross between a male horse and a female donkey produces a mule. Mules are an example of:

hybrid infertility

The condition that occurs when an interspecies hybrid successfully develops but is unable to produce functional gametes is known as

hybrid sterility

The condition that occurs when an interspecies hybrid successfully develops but is unable to produce functional gametes is known as: Multiple choice question.

hybrid sterility

The inability of a mule to reproduce is an example of:

hybrid sterility

Postzygotic isolating mechanisms prevent successful interbreeding among members of different species. Hybrid __ results when a zygote cannot successfully develop past the early stages of embryonic development. Hybrid __ results when an interspecies hybrid zygote reaches maturity but cannot produce viable gametes. Hybrid __ results when a hybrid is able to produce offspring with other hybrids, but subsequent generations harbor deleterious genetic abnormalities.

inviability sterility breakdown

A potential consequence of polyploidy is immediate reproductive

isolation

What is an example of hybrid sterility, a postzygotic isolating mechanism?

mating between a horse and donkey to produce a mule

The inability of members of two different species of dragonfly to mate because the grasping appendages of the male do not fit the body shape of the female is an example of ______ isolation.

mechanical

Members of two different species of dragonfly can not mate because the grasping appendages of the male do not fit the body shape of the female. This is an example of:

mechanical isolation

Physical traits such as height, weight, the color of a frog's skin, or the shape of a bird's beak are also known as ______ traits.

morphological

The most commonly used characteristics to identify species are __ traits, ability to __ , molecular features, ecological factors, and __relationships.

morphological interbreed evolutionary

The condition in which an organism has more than two sets of chromosomes is known as:

polyploidy

What mechanism can cause immediate reproductive isolation and lead to sympatric speciation?

polyploidy

A category of reproductive isolating mechanisms called __ isolating mechanisms prevent the formation of a zygote and include gametic or mechanical isolation.

prezygotic

Reproductive isolating mechanisms fall into two main categories: __ isolating mechanisms and __ isolating mechanisms.

prezygotic postzygotic

__ isolating mechanisms prevent the formation of a zygote, whereas __ isolating mechanisms come into play after the zygote is formed.

prezygotic postzygotic

A reproductive isolating mechanism that prevents the formation of a zygote is called ______, whereas ______ isolating mechanisms come into play after the zygote is formed.

prezygotic; postzygotic

The splitting or diverging of a population into two or more __ is known as cladogenesis.

species

Divergence of populations of apple maggots and pea aphids based on their preferred host plant, populations of cichlids based on female choice of male coloration, and immediate reproductive isolation of Galeopsis tetrahit (hemp nettle) because of allopolyploidy are all examples of events leading to __ speciation.

sympatric

Interspecies hybridization that results in polyploid offspring, sexual selection by females based on male behavior, differences in toleration of contaminants in soil, and host plant preference are all circumstances that could potentially lead to __ speciation.

sympatric

Speciation among populations that occur in the same area with no physical barriers to interbreeding is called __ speciation

sympatric

If two sympatric species of trees release pollen at different times of the year, what type of prezygotic isolation keeps these two species reproductively isolated?

temporal

Four species of frogs live in the same area; however, their peak breeding seasons are at different times of the year. This is an example of

temporal isolation

Two species that have similar morphological characteristics but reproduce at different times of the day or year are experiencing:

temporal isolation

The difference between allopatric and sympatric speciation depends on whether:

the populations undergoing speciation live in the same geographic area