Chapter 13 Mastering Biology

Which of the following represents a pair of homologous structures?

the wing of a bat and the flipper of a whale

The first tetrapods (four-legged animals) were amphibians, which evolved from a specialized group of lobed-fin fish. An unusual fossilized animal (named Tiktaalik) was recently found; this animal possessed a mixture of fish and amphibian characteristics. What is the term used to describe such an intermediate organism?

transitional form

When they were first sold, certain insecticides were highly effective in killing mosquitoes. Today, dozens of mosquito generations later, a much smaller proportion of these insects die when sprayed with the same chemicals. Fewer insects are killed today because _____.

many mosquitoes today are descendants of mosquitoes with insecticide-resistant characteristics

Darwin was the first person to draw an evolutionary tree, a diagram that represents

evidence-based hypotheses regarding our understanding of patterns of evolutionary descent.

The core theme of biology, which explains both the unity and diversity of life, is

evolution.

Experiments and observations indicate that natural selection acts _____.

fairly quickly in some circumstances (within a few generations), and often temporarily in response to changes in the immediate environment

The wing of a bat is homologous to the _____ of a whale.

flipper

The Argentinean pampas are a type of _____.

grassland

In Europe at the time Darwin voyaged on HMS Beagle, the popularly accepted explanation of the origin of Earth's plants and animals held that the various species __________.

had been created rapidly by a divine creator a few thousand years before

Species in hot climates tend to _____ compared to species in cold climates.

have larger surface-to-volume ratios

Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of

homology.

Which of the following list of assumptions was part of Charles Darwin's theory of natural selection?

1. Organisms vary in heritable ways. 2. Some traits improve the survival and reproduction of individuals who possess them. 3. Populations produce more offspring than their environment can support, so individual organisms must compete for limited resources. 4. Earth and its life are very old.

How many finch species did Darwin send to the British Museum?

13

Why were the Galápagos Islands so important to Darwin's formulation of natural selection?

Each island in the Galápagos possessed unique species.

Imagine that four people are infected with HIV from a common source (an infected blood sample). Initially, the patients' HIV populations are genetically identical. By the time they develop full-blown AIDS, how would the viral populations of the four patients compare?

Each patient's viral population would be unique, specifically adapted to deal with—and overcome—his or her unique immune system responses.

Which of the following best expresses the concept of natural selection?

differential reproductive success based on inherited characteristics

Which of these is a consequence of uniformitarianism?

Earth is very old.

Lyell's book Principles of Geology, which Darwin read on board the H.M.S. Beagle, argued in favor of which of the following concepts?

Earth's surface is shaped by natural forces that act gradually and are still acting.

Which option best describes the concept of an evolutionary tree diagram?

Evolutionary trees relate species to each other by ancestry. An ancestor common to all of the species is placed at the root of the tree. Branch points are defined by homologous features that are shared by the descendant species along a particular branch.

Which of the following is a true statement about Charles Darwin?

He proposed natural selection as the mechanism of evolution.

As proposed by Darwin, what sorts of traits are favored by natural selection?

Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

The Galápagos Islands are cooled by the _____.

Humboldt Current

Which of the following would prevent an organism from becoming part of the fossil record when it dies?

It is fully decomposed by bacteria and fungi.

Darwin's thinking while on the Beagle was greatly influenced by his reading of a book written by _____.

Lyell

Which of the following statements regarding natural selection is false?

Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness.

According to this climatograph, London experiences more precipitation during _____ than during any other month.

October

The Galápagos Islands are located _____.

Off the coast of Ecuador

The human immune system cannot effectively suppress the HIV virus on its own. What key feature of HIV makes it so hard to beat?

The HIV virus has an extremely high rate of mutation.

Which of the following statements regarding the currently available fossil record is false?

The currently available fossil record shows that the first life-forms were eukaryotes.

The forelimbs of humans, cats, and bats have a number of detailed similarities in their construction. What best explains these similarities?

The forelimbs are similar because all of these organisms inherited the basic forelimb design from a common ancestor.

Which best describes the fossil record?

The fossil record is the highly ordered sequence in which fossils are found in layers of sedimentary rock.

A population of small fish lives in a lake with a sandy bottom. The major predator of these fish is a wading bird that hunts by sight. Most of the fish are light sandy brown, but about 10% are mottled. The color pattern is heritable. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction?

The proportion of mottled fish will increase over time.

What was significant to Darwin about the fauna and flora of the Galápagos Islands?

The species were similar to South American species, indicating common descent, but they had been extensively modified and were well-adapted to island life.

Which of the following thinkers argued that much of human suffering was the result of human populations increasing faster than food supply, an argument that later influenced Charles Darwin's ideas of natural selection?

Thomas Malthus

If members of a population have traits that are both heritable and variable among individuals, then _____.

advantageous traits will probably become more widespread in subsequent generations

Which of the following assumptions or observations is not part of Darwin's idea of natural selection?

Whether an organism survives and reproduces is almost entirely a matter of random chance.

Natural selection is best described as _____.

a filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations

All known organisms use genetic information to produce protein molecules via the same genetic code. This finding strongly supports the hypothesis that __________.

all organisms are descended from one or a few common ancestors

What evidence is used to determine the branching sequence of an evolutionary tree?

anatomical or molecular homologous structures

HIV has become an important source of mortality for humans. If AIDS persists as a major factor for humans for many generations in the future, natural selection theory predicts that _____.

any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time

German shorthaired pointers, Scottish terriers, and Beagles are capable of interbreeding and producing viable, fertile offspring. The diversity seen in these breeds of dogs is the result of __________.

artificial selection

Broccoli, cabbages, and Brussels sprouts all descend from the same wild mustard and can still interbreed. These varieties were produced by

artificial selection.

His experiences with Fuegians and slavery convinced Darwin that differences among all peoples are primarily _____ differences.

cultural

Patagonia is a _____.

desert

At the fossil site at Punta Alta, Darwin found evidence _____.

of extinction

Which best summarizes the order of appearance of major life-forms (from earliest to most recent) and the time at which life first appeared as documented by the fossil record?

prokaryotes, unicellular eukaryotes, multicellular eukaryotes, with the oldest life-forms appearing about 3.5 billion years ago

Darwin found that many of the species on the Galápagos islands

resembled species on the nearest mainland.

Organisms that possess homologous structures probably __________.

share a common ancestor that also had this structure

Aristotle believed that

species are fixed (permanent) and perfect.

In the Andes, at elevations of 12,000 feet, Darwin collected fossilized marine shells. The existence of marine shells at this altitude provided evidence that _____.

the deposit had been gradually uplifted to its present location