Bio 1108 ch 19 hw:

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals.2. A change occurs in the environment.3. Genetic frequencies within the population change.4. Poorly adapted individuals have decreased survivorship.

2 → 4 → 1 → 3

A farmer wishes to develop a strain of high-yield corn that is also resistant to drought. He has the following individuals from the current year's crop:Individual A—Yield: 179 bushels/acre; drought resistance: highIndividual B—Yield: 220 bushels/acre; drought resistance: lowIndividual C—Yield: 185 bushels/acre; drought resistance: mediumIndividual D—Yield: 140 bushels/acre; drought resistance: highIndividual E—Yield: 200 bushels/acre; drought resistance: mediumWhich of the following crosses would produce the highest corn yield with the highest resistance to drought?

A and E This cross would result in an average corn yield of 189.5 bushels/acre and have a medium-high drought resistance, which is the best you can get for both traits.

Which of the following organisms could be produced by artificial selection?

A cow that produces a large quantity of milk. A cow's ability to produce milk is a heritable trait that can be manipulated by artificial selection.

Which term describes a trait that increases an individual's ability to survive in a particular environment?

Adaptation An adaptation is a trait that increases an individual's ability to survive in a particular environment.

Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?

All organisms use essentially the same genetic code.

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception?

Characteristics acquired during an organism's life are not passed on through genes.

What was the prevailing belief prior to the time of Lyell and Darwin?

Earth is a few thousand years old, and populations are unchanging.

Which term describes the ability of a trait to be passed on to offspring?

Heritability Heritability is the ability of a trait to be passed on to offspring.

What must be true of any organ that is described as vestigial?

It must be homologous to some feature in an ancestor.

Which pair of chickens should a farmer breed to produce larger chickens?

Large hen, large rooster Large parents should be bred to produce larger offspring.

Which of the following statements about natural selection is true?

Natural selection favors individuals that reproduce more than others. Individuals who are better able to survive and reproduce are more likely to be selected for than individuals who don't survive or cannot reproduce.

Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?

Populations tend to increase at a faster rate than their food supply normally allows.

Within the past century, humans have been eating higher cholesterol and fatty meals and have become less physically active, which makes them more susceptible to heart disease. Which of the following will lead to an adaptation?

Some people's bodies are able to break down cholesterol and fat more efficiently than others.

Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which of the following statements is true?

Species X and Y share a greater number of homologies than with species Z.

A large community of rattlesnakes, from El Paso, Texas, is separated into two groups. One group is taken 46 miles northwest to Las Cruces, New Mexico. The other group goes 712 miles north to Estes Park, Colorado. Which of the following statements is most accurate?

The group moved to Estes Park will undergo a series of adaptations to survive.

Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?

Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.

Evolution is best defined as which of the following?

a change in genetic composition of a population from generation to generation

Which of the following is an example of artificial selection?

a farmer cultivating sweet watermelons

Darwin's observation of the Galápagos Islands finches' various beaks and behaviors could be explained by

adaptations forged by natural selection.

If you wanted to find the largest number of endemic species, you should visit which of the following geological features (assuming each has existed for several millions of years)?

an isolated ocean island in the tropics

Of the following anatomical structures, which is homologous to the bones in the wing of a bird?

bones in the flipper of a whale

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of

convergent evolution.

What environment stimulates evolution of drug-resistant pathogens?

excess antibiotics

Which of the following must exist in a population before natural selection can act upon that population?

genetic variation among individuals

Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals?

homologous; analogous

Artificial selection is

human-directed selective breeding.

The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because

humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin.

Lamarck's contribution to evolutionary theory was the

idea that evolutionary change explains patterns in fossils.

What are adaptations?

inherited characteristics of organisms that enhance their survival and reproduction in specific environments

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that

island forms and mainland forms descended from common ancestors.

Fossils are found in

sedimentary rocks.

Analogous features share ________ function but not ________ ancestry.

similar; common

An article in the New York Times stated the following: "Scientists have discovered micro-organisms living beneath the ocean floor that appear to have not evolved for more than two billion years, a finding that nonetheless may support the theory of evolution." The lack of evolution of these microorganisms could be caused by

the bacteria's unchanging environment.

If two modern organisms are distantly related in an evolutionary sense, then one should expect that

they should share fewer homologous structures than two more closely related organisms.

Darwin viewed the history of life as a tree, as depicted in the figure, with multiple branchings from a common trunk to the tips of the twigs. Which part of that tree represents extant organisms?

tips of the twigs