ENVS Chapter 4

Fossils tell us about the long history of life on the earth and so far, our fossil record probably represents ____ of all species that have ever lived.

1%

Mass extinctions, with 25−95% of species going extinct, have occurred how many times in the history of the earth?

3-5

The earth has sustained life for ____ years.

3.5 billion

According to the International Union for Conservation of Nature (IUCN), about ____% of all known amphibian species are threatened with extinction.

33

Who was responsible for providing a convincing explanation of how organisms change over time and are descended from a single common ancestor through the mechanism of natural selection?

Charles Darwin and Alfred Russel Wallace

A temperate rain forest is likely to have high species evenness and low species richness

False

In speciation, two species interbreed to form one new species.

False

Many of the world's amphibian species are adapting rapidly to the environmental changes that are taking place in their habitats, which have been caused by human activities during the past few decades.

False

The fossils found so far probably represent about 50% of the species that have ever lived.

False

Under rapidly changing environmental conditions it is better to be a specialist species.

False

From a scientific point of view, which of the following is true?

Fitness is a matter of reproductive success.

Why do species such as humans take a much longer time (thousands to millions of years) to adapt through natural selection than species such as bacteria and insects?

Species such as humans are limited by reproductive capacity.

Which of the following is true?

The higher the species richness, the more the sustainability

Which of the following is true of specialist species?

They can tolerate a narrow range of climatic conditions.

Endemic species are particularly vulnerable to extinction.

True

Estimates indicate the average annual background extinction rate is one species lost for each million species on earth per year.

True

Genetic engineering allows scientists to transfer genes between different species that would not interbreed in nature.

True

In geologic history, mass extinctions have been followed by an increase in species diversity.

True

Keystone species have a large effect on the types and abundances of other species in an ecosystem.

True

Long-term climate changes determine where plant and animal species can survive.

True

Survival of the fittest refers to those individuals that leave the most descendants.

True

Research performed by Edward O. Wilson on ____ has been applied to the study and understanding of other social organisms, including humans.

ants

The fact that tectonic plates drift influences evolution by ____.

changing the earth's climate

The variety of terrestrial and aquatic ecosystems found in an area or on the earth is called ____.

ecological diversity

The role a species plays in its ecosystem is its ____.

ecological niche

The scientific study of insects is called ____.

entomology

The process whereby the earth's life changes over time through changes in genes of populations of organisms in succeeding generations is called ____.

evoluion

In some habitats, the extinction of certain amphibian species could lead to the ____ of certain species of other amphibians, aquatic insects, reptiles, birds, fish, and mammals.

extinction

Most mutations occur because of exposure to artificial external agents, such as radiation.

false

What is the variety of processes, including matter cycling and energy flow within ecosystems, which result from species interacting with one another in food webs?

functional diversity

A species with a broad niche is considered a

generalist species

The diversity that enables life on the earth to adapt and survive environmental changes is called ____.

genetic diversity

Scientists are now able to produce desirable traits in some organisms by adding, deleting, or changing segments of its DNA. This process is known as ____.

genetic engineering

What is the ability of one or more organisms in a population to tolerate a chemical designed to kill it, such as when bacteria tolerate antibiotics?

genetic resistance

The variety in the genetic makeup of individuals in a population is known as ____.

genetic variability

Which of the following is least associated with biodiversity?

geological diversity

Today, the ____ is among the most threatened of all species in the world, with only 1,600 to 3,000 individuals left in the wild.

giant panda

Before conservation efforts facilitated their comeback, the American alligator population was nearly completely wiped out primarily because of ____.

hunters

Species that provide early warnings of damage to a community or an ecosystem are called ____.

indicator species

Many of the earth's plant species depend on ____ to pollinate their flowers.

insects

Which of the following is another name for a nonnative species?

invasive

The loss of a(n) ____ can lead to population crashes and extinctions of other species in a community that depends on them for certain ecosystem services.

keystone species

When a species becomes extinct over a large region, but not worldwide, it is called ____.

local extinction

According to some scientists, the more diverse an ecosystem is, the ___ it will be.

more productive

For natural selection to occur, an adaptive trait ____.

must be a heritable trait

Biological evolution by natural selection is when genes ____, individuals ____, and populations ____.

mutate; are selected; evolve

Changes in the DNA molecules of a gene in any cell that can be inherited by offspring are called ____.

mutations

The process in which individuals with certain traits are more likely to survive and reproduce under a particular set of environmental conditions than are those without the trait is called ____.

natural selection

One contributing factor of the declines in many frog species is that frog eggs have ____.

no shells to protect frog embryos from water pollutants

What adaptation has allowed humans to increase our chances of survival and reproduction through gripping and using tools?

opposable thumbs

What human adaptation may enable us to live more sustainably by understanding and copying the ways in which nature has sustained itself for billions of years, despite major changes in environmental conditions?

our complex brain

Which of the following would not be considered a generalist species?

pandas

Non-native species can spread rapidly if they find a new location with favorable conditions, often because they do not face the same ____ that they face in their native niches.

predators

Which of the following would be the least likely cause for the decline of amphibians?

prolonged rainy periods

Compounds found in the ____ of certain amphibians have been isolated and used in pharmaceutical products.

skin secretions

Geographic isolation may result from ____.

speciation

Under certain circumstances, natural selection can lead to an entirely new species. a process called ____.

speciation

The earth's biodiversity is determined by the balance between ____.

speciation and extinction

A measure of the relative abundance, or the comparative numbers of individuals of each species present, is called ____.

species evenness

What term describes the number of different species in a given area?

species richness

The four components of biodiversity increase the ____ of ecosystems and increase the resistance of ecosystems to harmful invasive species.

stability

Which of the following does not describe an element of an ecological niche?

the place where the species lives

Biodiversity is a vital part of the natural capital that sustains all life.

true

Most of what we know about the history of life on the earth comes from fossils.

true

What are amphibians?

vertebrates that live part of their lives in water and part on land