Campbell AP Biology Mastering Biology Chapter 25 First Dynamic Module

Why is the four-stage hypothesis for the abiotic origin of life useful?

It leads to predictions that can be tested.

Single-celled prokaryotes had the Earth to themselves for approximately __________.

1.5 billion years

What does the snowball Earth hypothesis propose?

Larger multicellular eukaryotes are scarce in the fossil record until the late Proterozoic because an ice age limited life to deep-sea vents and hot springs.

Currently scientists think the early atmosphere probably consisted of __________.

N2, H2O, CO2, NH3, CH4, H2, and H2S

The early atmosphere may not have been as reducing as originally postulated by Haldane, Oparin, Miller, and Urey. In light of current thinking about the composition of the early atmosphere, what is regarded as a likely place for the abiotic synthesis of organic molecules to have occurred?

Near volcanoes

What were the two major "problems" that had to be solved before plants, animals, and fungi could move into terrestrial habitats?

Reproduction and prevention of dehydration

What evidence most strongly suggests that an impact by an asteroid or meteorite may have caused the extinction of the dinosaurs?

Sedimentary rocks contain a layer of iridium, a mineral uncommon on Earth.

In the species selection model, __________ is to macroevolution as __________ is to microevolution.

differential speciation success; differential reproductive success

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of __________.

exaptation

If the wings of extant flying birds originally arose as thermoregulatory devices in ancestral reptiles, then the bird wings could be accurately described as __________.

exaptations

Plants colonized land in the company of __________; their symbiotic relationships still exist today.

fungi

Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.

genetic drift

The products of Hox genes __________.

provide positional information in animal embryos

Fossilized stromatolites __________.

resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays

The Miller and Urey abiotic synthesis experiment (and subsequent, similar experiments) showed that __________.

simple organic molecules can form spontaneously under conditions like those thought to prevail early in Earth's history

How does continental drift affect speciation?

All of the listed responses are correct.

The fauna and flora of Australia are very different from those of the rest of the world. Why might this be true?

Australia has been isolated for about 50 million years.

Although they originated around 180 million years ago, mammals underwent an adaptive radiation starting approximately 65 million years ago. Why?

Between 180 and 65 million years ago, mammals were outcompeted by the well-established dinosaurs.

Mutations in what class of genes have probably been responsible for many of the changes leading to the great diversity of life existing today?

Developmental genes

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia?

India was a separate continent until 45 million years ago.

The early atmosphere on Earth is thought to have lacked which of the following gases?

Oxygen

The correct order of the geologic eras, from most ancient to most recent, is __________.

Paleozoic, Mesozoic, and Cenozoic

Prior to the Cambrian explosion, most animals were small and soft-bodied. What development appears to have spurred adaptations such as sharp spines, claws, and body armor (shells)?

Predation

Cech and Altman suggested that the first self-replicating molecules were __________.

RNA

Abiotically produced vesicles display which of the following rudimentary qualities necessary for life?

The ability to perform simple reproduction and metabolism

The oxygen revolution changed Earth's environment dramatically. Which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?

The evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules

Which of the following best describes how the breakup of Pangaea affected evolution?

The geographic isolation of populations that had previously coexisted led to speciation.

What evidence supports the hypothesis that mitochondria and plastids evolved from prokaryotic endosymbionts?

They have a single circular chromosome similar to bacterial chromosomes; their ribosomes are more like prokaryotic ribosomes than eukaryotic ribosomes

You are watching a movie in which one of the characters excitedly claims to have found human remains in Asia dated at 10 million years old. The date was obtained by carbon-14 dating. What is your reaction?

This can't possibly be true because carbon-14 dating can only be used back to about 75,000 years.

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of __________.

a change in a developmental gene or in its regulation that altered the spatial organization of body parts

Lake Malawi, in the African Rift Valley, is home to more than a hundred species of cichlid fishes, each with slightly different diets and habits. All these species probably evolved from a common ancestor, making them an example of __________.

adaptive radiation

Ancient cyanobacteria were very important in the history of life because they __________.

produced atmospheric oxygen