Question 1

What percentage of the world's known plant species have been examined for medicinal properties?

Accepted Answer

A

Question 2

The estimate of the background extinction rate is thought to be too low. Which explanation for why the estimate may be low is false ?

Accepted Answer

The false explanation is that the growing human population is using fewer resources per person. In reality, the growing human population tends to use more resources per person, which contributes to habitat destruction, pollution, and overexploitation of species, thereby increasing the extinction rate.

Question 3

The key role of a honeybee is to ____ plants and flowers.

Accepted Answer

Honeybees play a vital role in pollinating plants and flowers, which is essential for the growth and reproduction of many crops and plant species. Without honeybees, many plants would not be able to reproduce and provide food for other animals and humans.

Question 4

After a mass extinction, what happens to biodiversity rates?

Accepted Answer

After a mass extinction, biodiversity rates typically recover over millions of years as new species evolve and ecosystems rebuild. It takes time for the surviving organisms to adapt and fill the niches left by the extinct species. The process is often slow and gradual, and it may take several more rounds of speciation and extinction before biodiversity rates stabilize at a "new normal."

Question 5

Biodiversity experts estimate that during this century, the extinction rate due to human activities will rise to ____ times the background extinction rate.

Accepted Answer

The answer of Biodiversity experts estimate that during this century,...

Question 6

Biodiversity hotspots are ____.

Accepted Answer

Biodiversity hotspots are areas with a high level of biodiversity and a significant number of species that are threatened with extinction. These areas are prioritized for conservation efforts because of their unique and irreplaceable ecological and evolutionary importance.

Question 7

Colony collapse disorder is ____.

Accepted Answer

Colony collapse disorder (CCD) is characterized by the sudden loss of a hive's worker bee population with very few dead bees found near the hive. The remaining few bees, including the queen, cannot sustain the hive, leading to its collapse. This phenomenon is not limited to any specific region and involves bees leaving the hive and not returning, rather than the disintegration of bee hives or effects following the queen's death.

Question 8

If estimates of an extinction rate 10,000 times greater than the background rate are correct, then what percentage of all species will be extinct by the end of this century?

Accepted Answer

The background extinction rate is about one species per million species per year. If the extinction rate is 10,000 times greater, then the extinction rate would be 10,000 species per million species per year. By the end of this century (100 years), there will be 10,000 x 100 = 1,000,000 species lost. The total number of species on Earth is estimated to be around 8 million, so 1,000,000/8,000,000 = 0.125 or 12.5%. This falls within the range of 25-50%, so the best answer is D.

Question 9

Because birds live in every climate and biome, and because they are easy to track and count, they serve as excellent ____.

Accepted Answer

Birds serve as excellent indicator species because their presence or absence can provide information about the health and quality of an ecosystem. Their sensitivity to environmental changes also allows scientists to monitor and track changes in ecosystems over time.

Question 10

The extinction of many species in a relatively short period of geologic time is called ____.

Accepted Answer

Mass extinction is the only option that accurately describes the extinction of many species in a short period of time. Secondary extinction and tertiary extinction are not widely recognized terms, while biological extinction and background extinction rate refer to the slower, ongoing process of species disappearance.

Question 11

____ are most threatened with extinction because of human activities.

Accepted Answer

Amphibians are the most threatened with extinction due to human activities such as habitat destruction, pollution, climate change, and the introduction of non-native species. Around 41% of amphibian species are currently at risk of extinction, according to the International Union for Conservation of Nature (IUCN). While other groups such as mammals and birds are also threatened, amphibians are particularly vulnerable due to their dependence on freshwater habitats and their sensitive skin which makes them susceptible to changes in their environment.

Question 12

Throughout the 3.5 billion year history of life on the earth, there has been a natural, low rate of species extinction know as ____.

Accepted Answer

The natural, low rate of species extinction throughout the history of life on earth is known as the background extinction rate. Mass extinction refers to a sudden and significant loss of species biodiversity within a short period of geological time. Secondary extinction refers to the extinction of species that rely on a particular species for survival, which has become extinct. Biological extinction refers to the complete disappearance of a species from the earth. Tertiary extinction is not a recognized term in the field of biology.

Question 13

The rate at which extinctions occurred prior to the evolution of modern humans is called the ____.

Accepted Answer

The term used to describe the rate of extinctions prior to modern humans is the background extinction rate. This refers to the normal rate of extinction that occurs as a result of natural processes, such as competition and natural disasters. The other choices, such as the E.O. Wilson postulate, species diversity index, and living planet index, do not specifically refer to the rate of extinctions prior to modern humans. The baseline extinction rate may be a plausible choice, but it is a less common term than the background extinction rate.

Question 14

Four of the following are characteristics that make some species especially vulnerable to ecological and biological extinction. One of the following is not such a characteristic. Which one is it?

Accepted Answer

The answer of Four of the following are characteristics that...

Question 15

An endangered species ____.

Accepted Answer

An endangered species is one that may soon become extinct over all or most of its range. This means that its population is decreasing significantly and it is at a very high risk of disappearing from its natural habitat.

Question 16

Bees use ____ to make ____.

Accepted Answer

Bees collect nectar from flowers and convert it into honey through a process of regurgitation and evaporation.

Question 17

Biologists think there are four major reasons why we should work to prevent human activities from causing the extinction of other species. Which of the following is not one of these reasons?

Accepted Answer

The four major reasons identified by biologists are: (A) species are part of the earth's life support system, (B) most species contribute to services that support our economies, (C) it will take from 5 million to 10 million years to rebuild the biodiversity, and (E) each species has a right to exist even if it isn't useful to us. Option D, which states that we need animals, especially rare animals, for zoos, is not a major reason why we should work to prevent species extinction according to biologists.

Question 18

What percentage of the world's 10,000 bird species is declining in number?

Accepted Answer

According to the International Union for Conservation of Nature (IUCN), around 70% of the world's 10,000 bird species are declining in number.

Question 19

Bioprospectors are ____.

Accepted Answer

Bioprospectors are people who search for plants and animals that have potential commercial value, including those that can be used to make medicinal drugs. They do not necessarily cause the extinction of plants and animals, nor do they decide which species should be protected. While bioprospectors may work alongside conservation biologists, their primary focus is on finding and exploiting resources, rather than promoting ecotourism.

Question 20

A threatened species ____.

Accepted Answer

The answer of A threatened species ____.
...

Quiz 9: Sustaining Biodiversity: The Species Approach