MBG 2040 Chapter Notes - Chapter 13: Gamete, Proflavine, Repressor Lexa

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amethystrat477

26 Nov 2012

School

University of Guelph

Department

Molecular Biology and Genetics

Course

MBG 2040

Professor

Dennis Baker

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Document Summary

The term mutation refers to both (1) the change in the genetic material and (2) the process by which the change occurs. Mutations that involve changes at specific sites in a gene are referred to as point mutations. They include the substitution of one base pair for another or the insertion or deletion of one or a few nucleotide pairs at a specific site in a gene. Some level of mutation is essential to provide new genetic variability so populations can evolve and adapt. Without mutation, all genes would exist in only one form no alleles. But if mutations occur too frequently, they disrupt the transfer of genetic information from generation to generation. Rate of mutation is influenced by genetic factors and mechanisms have evolved that regulate the level of mutation that occurs under various environmental conditions. Structures of the bases in dna are not static.

Related Questions

Random, chance events that change allele frequencies are knownas:

A. Gene flow

B. Genetic drift

C. Natural selection

D. Balancing selection

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Question 21 pts

What type of selection acts to maintain the two extremephenotypic variants in a population?

A. Disruptive selection

B. Directional selection

C. Positive selection

D. Artificial selection

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Question 31 pts

Approximately, how much of our DNA is shared with our closestrelatives, chimpanzees?

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Question 41 pts

The large canines of male baboons are likely the result of________, while the fact that some male baboons are very colorfulis probably the result of _______.

A. Mutation; balancing selection

B. Gene flow; sexual dimorphism

C. Male competition; female choice

D. Mate choice; genetic drift

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Question 51 pts

Negative assortative mating results in an increased frequency ofhomozygous genotypes within a population.

True

False

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Question 61 pts

Genetic evidence suggests that humans and Neandertals neverinterbred.

True

False

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Question 71 pts

The specific variant of the FOXP2 gene associated with languageacquisition in humans is found in both humans and Neandertals.

True

False

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Question 81 pts

Industrial melanism describes the change in moth color from paleto dark after pollution from factories resulted in coating treetrunks with a layer of dark soot. Which statement is trueconcerning industrial melanism?

A. After pollution levels increased, all moths became darkercolored because soot got on their wings

B. The dark moths survived better after pollution levelsincreased because they were not poisoned by the pollutants

C. Individual moths changed their color in response to thepollution

D. Dark moths were present in the population before pollutionlevels increased

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Question 91 pts

Patterns of evolution can be seen above the species level

True

False

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Question 101 pts

Inbreeding is problematic because it increases the probabilitythat offspring inherit two copies of a recessive mutation thatcauses disease.

True

False

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Question 111 pts

As a species, cheetahs seem to have a high risk of extinctionbecause:

A. Gene flow has caused a proliferation of unnecessarygenes.

B. The species' genetic diversity is very low due to a previouspopulation bottleneck event.

C. The species has undergone extreme sexual selection in orderfor males to achieve faster running speeds.

D. Gene flow has been stifled due to an increase in demand forcaptive cheetahs.

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Question 121 pts

A strand of DNA undergoes mutation. Which mutation occurred?

Original DNA- GGA CTC TTA CCC CAC GGA

Mutated DNA- GGG CTC TTA CCC CAC GGA

A. point mutation

B. insertion mutation

C. deletion mutation

D. inversion mutation

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Question 131 pts

A change from one nucleotide to another nucleotide is known as awhat?

A. Point mutation

B. Insertion mutation

C. Deletion mutation

D. Inversion mutation

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Question 141 pts

A change from one nucleotide to another nucleotide is known as awhat?

A. point mutation

B. insertion mutation

C. deletion mutation

D. inversion mutation

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Question 151 pts

According to the Typological Species Concept, species are:

A. An interbreeding group of organisms

B. Static entities endowed with fixed properties

C. A local population of organisms that have similargenes, interbreed, and produce offspring

D. An exclusive community of gene exchange

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Question 161 pts

Recognizing reproductive isolation is key to defining speciesunder the Biological Species Concept.

True

False

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Question 171 pts

The binomial system of classification was developed by:

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Question 181 pts

A derived trait, unique to a particular taxon within a givencladogram is called:

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Question 191 pts

Analogy, and not homology, is useful for reconstructingevolutionary history.

True

False

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Question 201 pts

A phylogeny is which of the following:

A. A depiction of an organism's complete genome

B. A depiction of evolutionary relationships betweenorganisms

C. The gradual evolution of one species intoanother

D. The Latin name of an organism including its genus andspecies designation

coffeegoat763

Some of you will have seen Starship Troopers, a moviebased upon a novel by Robert Heinlein. The film deviates from thebook in some ways, for example the book describes a visit to aplanet to resupply the dropships used in combat operations by theM.I. (mobile infantry). Heinlein describes this visit in the book;a portion of the novel is reproduced on the followingpage.

The followig passage contains two concepts we havediscussed in class in relation to the effects of mutation onpopulations, one positive and one negative. Describe the twomutation related concepts Heinlein discusses. You must describethese concepts as a biologist - you must use the technical terms wehave used in class properly and explain the positive and negativeeffect of mutation on the evolution and health of apopulation.

(a) What is the positive effect of mutation as describedby Heinlein?

(I.E., what does Heinlein describe as a benefit ofhaving more mutations)

(b) What is the negative effect of mutation as describedby Heinlein?

(I.E., what does Heinlein describe as a problem ofhaving more mutations)

I never have learned the co-ordinates of Sanctuary,nor the name or catalogue number of the star it orbits - becausewhat you donât know, you canât spill; the location isultra-top-secret, known only to shipâs captains, piloting officers,and such ... and I understand, with each of them under orders andhypnotic compulsion to suicide if necessary to avoid capture. So Idonât want to know. With the possibility that Luna Base might betaken and Terra herself occupied, the Federation kept as much ofits beef as possible as Sanctuary, so that a disaster back homewould not necessarily mean capitulation.

But I can tell you what sort of a planet itis. Like Earth, but retarded.

Literally retarded, like a kid who takes tenyears to learn to wave bye-bye and never does manage to masterpatty cake. It is a planet as near Earth as two planets can be,same age according to the planetologists and its star is the sameage as the Sun and the same type, so say the astrophysicists. Ithas plenty of flora and fauna, the same atmosphere as Earth, nearenough, and much the same weather; it even has a good-sized moonand Earthâs exceptional tides.

With all these advantages it barely got awayfrom the starting gate. You see, itâs short on mutations; it doesnot enjoy Earths high level of natural radiation.

Its typical and most highly developed plantlife is a very primitive giant fern; its top animal life is aproto-insect which hasnât even developed colonies. I am notspeaking of transplanted Terran flora and fauna - our stuff movesin and brushes the native stuff aside.

With its evolutionary progress held down toalmost to zero by lack of radiation and a consequent mostunhealthily low mutation rate, native life forms of Sanctuary justhavenât had a decent chance to evolve and arenât fit to compete.Their gene patterns remain fixed for a relatively long time; theyarenât adaptable - like being forced to play the same bridge handover and over again, for eons, with no hope of getting a betterone.

As long as they just competed with eachother, this didnât matter too much - morons among morons, so tospeak. But when types that had evolved on a planet enjoying highradiation and fierce competition were introduced, the native stuffwas outclassed.

Now all the above is perfectly obvious fromhigh school biology ... but the high forehead from the researchstation there who was telling me about this brought up a point Iwould have never thought of.

What about the human beings who havecolonized Sanctuary?

Not transients like me, but the colonists wholive there, many of whom were born there, and whose descendantswill live there, even unto the umpteenth generation - what aboutthose descendants? It doesnât do a person any harm not to beradiated; in fact itâs a bit safer - leukemia and some types ofcancer are almost unknown there. Besides that, the economicsituation is at present all in their favor; when they plant a fieldof (Terran) wheat;, they donât even have to clear out the weeds.Terran wheat displaces anything native.

But the descendants of those colonists wonâtevolve. Not much, anyhow. This chap told me that they could improvea little through mutation from other causes, from new blood addedby immigration, and from natural selection among the gene patternsthey already own - but that is all very minor compared with theevolutionary rate on Terra and on any usual planet. So whathappens? Do they stay frozen at their present levels while the restof the human race moves on past them, until they are livingfossils, as out of place as a pithecanthropus in a spaceship?

Or will they worry about the fate of theirdescendants and dose themselves regularly with X-rays or maybe setof lots of dirty-type nuclear explosions each year to build up afallout reservoir in their atmosphere? (Accepting, of course, theimmediate dangers of radiation to themselves in order to provide aproper genetic heritage of mutation for the benefit of theirdescendants.)

This bloke predicted that they would not doanything. He claims that the human is too individualistic, tooself-centered, to worry that much about future generations. He saysthat the genetic impoverishment of distant generations through thelack of radiation is something most people are simply incapable ofworrying about. And of course it is a far-distant threat; evolutionworks so slowly, even on Terra, that the development of a newspecies is a matter of many, many thousands of years.

I donât know. Shucks, I donât know what Imyself will do more than half the time; how can I predict what acolony of strangers will do? But Iâm sure of this: Sanctuary isgoing to be fully settled, either by us or by the bugs. Or bysomebody. It is a potential utopia, and, with desirable real estateso scarce in this end of the Galaxy, it will not be left in thepossession of primitive life forms that failed to make thegrade.

As temperatures in an African savanna increase and rainfall decreases, it would most likely change into

tiaga

desert

tropical rainforest

temperate forest

What is imprinting? Give an example.

fixed assocation, such as hatching ducks recognizing the first animal they see as their mother

a learned behavior, such as a wasp circling during a search for food, so that it can return to its nest

alteration of instinct, such as a spider changing the type of web it weaves depending upon the environment

Opportunistic species

provide extensive care for their offspring

produce many offspring

reproduce later in life

What are the five agents of microevolution?

gamete production; mating; fertilization; caring for offspring; formation of herds

photosynthesis; respiration; mitosis; meiosis; fertilization

mutation; gene flow; nonrandom mating; genetic drift; natural selection

Microevolution is

new species

minor extinction of species

changes in allele frequency in a population

Which of the following is does not help defend against predators?

Toxins made by plants that injure caterpillars feeding on the plant

The large eyespots on a moth's wing that can startle a hungry bird

Thorns on a plant

Many plants have brightly colored fruit and flowers

Humans have a favored birth weight, neither too small nor too large. This is

stabilizing selection

disruptive selection

artificial selection

directional selection

What is a keystone species?

the first organism that populates an area

an organism upon which the entire ecosystem depends

the first fossils found in the earliest rock strata

As temperatures in the Arctic warm, which of the following changes may occur?

Tundra will be replaced by taiga

Taiga will be replaced by tundra

Temperate forest will be replaced by taiga

Tundra will be replaced by desert

Taiga will be replaced by temperate rain forest

What is desertification?

restoration of vegetation and water to deserts

areas adjacent to deserts also become deserts

abandonment of a habitat by animals

Evolution occurs at the level of

individuals

populations

communities

The maximum population that the environment can support is called the

biotic potential

environmental resistance

carrying capacity

replacement reproduction

demographic transition

A population with relatively more pre-reproductive individuals is common in _____-developed countries

less

Endangered species sometimes breed in captivity. Why are such species endangered in the wild?

Their population density is too high

Loss of habitat

Their environment is polluted

Abiotic components of an ecosystem include

only animal life

only plant life

living components only

nonliving components only

both living and nonliving components

Carbon returns to the atmosphere

as carbon dioxide

from respiration of plants

by the burning of fossil fuels

from respiration of animals

All of the answer choices are correct

Why does the Tropical Rain Forest contain an abundance of antibiotic compounds?

The area is crowded, leading to random production of useful compounds

The area is wet. plants had to develop resistance to fungi and bacterial infections

There is a great diversity of plants, leading to random production of useful compounds

The carrying capacity of the environment for a species is determined by

the reproductive rate of the organism

the number of organisms of that species

the state and national wildlife laws pertaining to that species

a complex

the limited productivity of the environment and the environmental resistance to the biotic potential of the organism

An introduced species that breeds and spreads is

resourceful

harmful

native

dominant

invasive

What is disruptive selection?

environmental influences that select against change

environmental influences that promote one phenotype versus all others

environmental influences that promote two or more phenotypes versus all others

Natural selection acts on

individuals

populations

communities

Two populations of birds live in the same area but have different sleep/wake cycles. This is

behavorial isolation

mechanical isolation

geographical isolation

temporal isolation

An insect that resembles the face of a snake avoids predation by

camouflage

warning coloration

mimicry

chemical defense

mutualism

Unselfish acts that help others in a group so that they increase their chances of surviving and reproducing is called

imprinting

mimicry

altruism

learning

instinct

If an environment changes rapidly, organisms with ____ will be more likely to survive and reproduce.

the correct allele frequency

existing neutral mutations

existing beneficial mutations

How did geology influence Darwinâs thoughts?

It demonstrated that the earth was very old, therefore there was enough time for species to evolve

it demonstrated that all continents were similar

it demonstrated the presence of many fossils

The founder effect occurs when

large groups of individuals leave their home population and establish new settlements, mating only among themselves

many members of a population die, resulting in a great loss of genetic diversity

many members of a population reproduce causing too much genetic diversity within the population

small groups of individuals leave their home population and establish new settlements, mating only among themselves.

The greenhouse effect is due to high atmospheric

Nitrogen

Ammonia

Carbon monoxide

Carbon dioxide

Oxygen

What are the Reproductive Barriers that keep species separate?

lack of food; lack of habitat; lack of potential mates; lack of nesting sites; lack of genetic variation

mountains; canyons; glaciers; bodies of water (for terrestrial animals); areas of land (for aquatic animals)

habitat isolation; temporal isolation; behavioral isolation; mechanical isolation; gamete isolation

What is directional selection?

environmental influences that select against change

environmental influences that promote one phenotype versus all others

environmental influences that promote two or more phenotypes versus all others

Which of the following is correct when describing a predator-prey cycle?

A decline in the numbers of predators causes a decline in the number of prey

A decline in the numbers of prey causes a decline in the number of predators

An increase in the number of predators triggers an increase in the number of prey

An up-and-down cycle will be seen for the prey animal

A seasonal die-off that will occur without the other species present

Why are top-level predators (lions, eagles, humans) so rare in a community?

Only a small amount of the energy is passed from one trophic level to the next

They do not breed as fast as other animals

Because of predation by higher predators

It is difficult for them to learn how to capture prey

Their job is to keep the population size of other animals in check

Alleles conferring bright color to male guppies are common because

they make males less visible to predators

they help males identify each other

they are preferred by females

Organisms that obtain their energy from producers or other consumers are

autotroph

heterotroph

producer

autotroph and producer

heterotroph and producer

What is the environmental impact of strip mining?

lack of trees exposes the surface of the earth, promoting runoff and loss of adjacent trees

removal of minerals from the soil hampers growth of vegetation

it causes a potential increase in volcanic activity

Two populations of squirrels are separated by a mountain range and would not be capable of interbreeding. This is an example of:

behavorial isolation

mechanical isolation

geographical isolation

temporal isolation

What is a danger of overfishing?

humans will become dependent upon fish

selection for smarter fish that can avoid being caught

driving the population back into the lag phase

What is meant by prezygotic versus postzygotic speciation mechanisms?

before versus after formation of a zygote

before versus after meiosis

before versus after gamete formation

The relatively short term changes in allele frequencies within a species or population is

artificial selection

microevolution.

speciation

macroevolution

Avoidance of a location with predators is the result of

imprinting

mimicry

altruism

learning

instinct

What is the difference between Density-Dependent and Density-Independent Factors on populations?

density-dependent factors exert a greater influence when there are more individuals; density-independent exerts the same influence on all individuals regardless of their number

density-dependent factors exert a greater influence on larger, more dense individuals; density-independent factors exert the same impact on individuals of all size

density-dependent factors exert the same influence on all individuals regardless of their number; density-independent factors exert a greater influence when there are more individuals regardless of their number

All of the organisms in a given location or area is termed a

peer group

flock

community

population

herd

The concentration of the pesticide DDT would be highest in

a minnow

a mosquito larva

a seagull

plankton

algae

Our biosphere is

the Earth

the atmosphere

the ocean

land on Earth

fresh and salt water

What is meant by âcarrying capacityâ?

the amount of food produced in an ecosystem

the extent of energy required to maintain an ecosystem

the number of individuals that can be supported by an ecosystem

Species living on another is

resource partitioning

coevolution

symbiosis

predation

niche sharing

One species feeding on another is

competition

a community

an ecosystem

predation

symbiosis

Populations of different species interacting with one another in a natural environment is called

competition

a community

a biome

predation

symbiosis

Which of the following is not a biogeochemical cycle?

ATP cycle

water cycle

carbon cycle

phosphorus cycle

nitrogen cycle

Horses became larger and faster to escape predators. This is

stabilizing selection

disruptive selection

artificial selection

directional selection

MBG 2040 Chapter Notes - Chapter 13: Gamete, Proflavine, Repressor Lexa

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