Bio 111 Chapter 24 Connect

What type of isolation serves as a prezygotic isolating mechanism when a geographic barrier prevents different species from interbreeding?

habitat

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

polyploidy

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

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

hybrid infertility

What phenomenon causes a single ancestral species to evolve into a wide array of descendant species with diverse habitats, forms, or behaviors that occurs often as a result of colonization of a new area?

Adaptive radiation

A biologist discovers two populations of wolf spiders whose members appear identical. Members of one population are found in the leaf litter deep within the woods. Members of the other population are found in the grass at the edge of the woods. The biologist decides to designate the members of the two populations as two separate species. Which characteristics is this biologist most closely utilizing to distinguish species?

Ecological factors

The field of biology that compares the development of different organisms to understand their ancestral relationships is known as __________ ___________ biology

Blank 1: evolutionary or evo Blank 2: developmental or devo

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

Blank 1: hybrid Blank 2: 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.

Blank 1: inviability Blank 2: sterility Blank 3: breakdown

The most commonly used characteristics to identify species are __________ traits, ability to ___________ , molecular features, ecological factors, and __________ relationships.

Blank 1: morphological or physical Blank 2: interbreed, reproduce, or breed Blank 3: evolutionary

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

Blank 1: prezygotic Blank 2: postzygotic

An evolutionary scientist classified bacteria based on their use of resources (such as sugars and vitamins) and their growth conditions (such as temperature and pH). What type of evidence was used to classify these species?

Ecological factors

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

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. Mechanical isolation: Mating is attempted, but anatomical differences prevent the successful exchange of gametes.

Although morphological characteristics are often used to differentiate species, what are some drawbacks to this approach?

Many traits are continuous, such as size and weight. Members of the same species can look different. Different species can look similar.

Match the following organism characteristics with how they are used to distinguish different species.

Morphological characteristics --> Individuals that have similar physical features are classified to the same species. Reproductive isolation --> Organisms that are unable to produce viable and fertile offspring are classified to different species. Ecological factors --> Organisms that have similar habitat requirements, such as temperature, rainfall, and soil pH, are classified to the same species. Molecular features --> Organisms with similar DNA sequences are considered to be members of the same species. Evolutionary relationships --> Individuals that have descended from the same ancestor are members of the same species.

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.

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

Postzygotic isolating mechanisms

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

What type of speciation does not require a geographic barrier?

Sympatric speciation

Which of the following statements is TRUE regarding the relative frequencies of allopatric and sympatric speciation?

Sympatric speciation is thought to be much LESS common than allopatric speciation.

What is macroevolution?

The evolutionary changes that result in the formation of new species

Why do reproductive isolating mechanisms occur?

They are by-product of genetic divergence. As population adapts to environment, its unique traits may prevent interbreeding with other species

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.

The phenomenon that causes a single ancestral species to evolve into a wide array of descendant species with diverse habitats, forms, or behaviors that occurs often as a result of colonization of a new area is known as _________ radiation

adavptive

Of the following, which are examples of sympatric speciation?

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

Speciation that occurs as a result of physical separation of members of a species is known as __________ speciation.

allopatric

A physical separation of members of populations that causes speciation is known as:

allopatric speciation

Which of the following are methods used by biologists to distinguish different species?

assessing the ability of individuals of different groups to successfully interbreed analyzing DNA or other molecular sequences observing the outward appearance of individuals determining the organisms' ecological niches determining evolutionary relationships and lineages

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

The fact that Hox genes are found in all animals indicates that they originated very __________ in animal evolution.

early

Comparing the development of different organisms in an attempt to understand their ancestral relationships is associated with which of the following fields of biology?

evo-devo

Adaptive radiation occurs when organisms:

exploit a variety of new environments

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

True or false: Reproductive isolating mechanisms occur because members of populations intentionally want to maintain themselves as separate species.

false

Speciation most commonly occurs when

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

Match each prezygotic isolating mechanism with how it prevents successful interbreeding among different species.

geographic isolation --> Members of two different species never come into contact with one another because they live in different places. temporal isolation --> Species reproduce at different times of the day or year. behavioral isolation --> Members of different species differ in their mating rituals. mechanical isolation --> Structural differences between species prevent mating. gametic isolation --> Gametes are exchanged, but the egg is not successfully fertilized to produce a zygote.

Which of the following concepts suggests that each new species evolves continuously over long spans of time?

gradualism

In phenomenon known as heterochrony, genetic variation can influence the morphology of a species by controlling:

growth rates

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

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

Evolutionary changes in the rate or timing of developmental events are known as

heterochrony.

Match each postzygotic isolating mechanism with how it prevents successful interspecies hybridization.

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 sterility --> An interspecies hybrid zygote develops to maturity, but it is incapable of producing viable gametes. hybrid breakdown --> An interspecies hybrid is able to produce gametes and reproduce with other hybrids, but subsequent generations harbor detrimental genetic abnormalities.

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

hybrid sterility

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

hybrid sterility

In what organisms are Hox genes found?

in all animals

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

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

A potential consequence of polyploidy is immediate reproductive __________

isolation

One way of identifying a species is by its ability to interbreed. Indeed, the process by which members of one species are unable to successfully interbreed with members of another species is termed reproductive __________

isolation

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

macroevolution

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

What characteristics are often used to identify different species?

molecular features evolutionary relationships morphological traits ability to interbreed ecological factors

A scientist studying turtles on an island thought that the larger and smaller ones were separate species, but later realized they were female and male of the same species. What type of characteristic was the scientist using at first to distinguish species?

morphological

According to the punctuated equilibrium model:

most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.

The genome of each species encodes a unique set of morphological features that arise in embryonic development through coordinated cell division, migration, differentiation and cell death. This process is called __________ formation.

pattern

During embryonic development, coordination of cell division, cell migration, cell differentiation, and cell death leads to the morphological features encoded by the genome of that species --- a process called:

pattern formation

A genetic condition that can immediately cause reproductive isolation and lead to sympatric speciation is called __________ , in which an organism has more than two sets of chromosomes.

polyploidy

A category of reproductive isolating mechanisms called ___________ isolating mechanisms block the development of a viable and fertile individual after fertilization has taken place.

postzygotic, post zygotic, or post-zygotic

Isolating mechanisms that prevent reproductive attempts or make it unlikely that reproductive attempts will be successful are referred to as:

prezygotic reproductive isolating mechanisms

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

prezygotic, pre-zygotic, or pre zygotic

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

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

prokaryotes, bacteria, archaea, bacteria and archaea, archaea and bacteria, microorganisms, or microbes

A major suggestion of ______ is that during evolution there may be very long time periods where species remain essentially unchanged.

punctuated equilibrium

What type of isolation occurs when members of one species are unable to successfully interbreed with members of another species?

reproductive

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

sensory structures cell anatomy body shape

The formation of new species is a phenomenon known as __________

speciation

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

species

Hybrid __________ prevents successful interspecies hybridization because the hybrid is unable to produce viable gametes at maturity and so cannot reproduce.

sterility

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

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

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? Multiple choice question.

temporal

True or false: Heterochrony involves changes in growth rates that may lead to the differences in morphological characteristics observed in members of different species.

true

True or false: Morphology may be influenced by genetic variation that influences the relative growth rates of the body during development.

true

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.

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

alloploid

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

bacteria

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

cladogenesis

A defining characteristic of allopatric speciation is:

geographic isolation

Some of the morphological differences in closely related species may be attributed to genetic changes that affect growth rates of different body parts during development. What is this phenomenon called?

heterochrony

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

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

polyploidy

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

sympatric

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

temporal isolation