Question 1

As we study the past 50,000 years worth of information about species' decline and extinctions around the world

Accepted Answer

The pattern observed over the past 50,000 years is that there are rapid extinctions, especially of larger animals, soon after humans arrive in a new area. This is known as the "overkill hypothesis" and has been observed in multiple regions around the world.

Question 2

Which of the following groups is most studied regarding the increasing extinctions today?

Accepted Answer

B

Question 3

Scientists speculate that extinctions did not occur in Africa as they did on other continents because animals coevolved with _______ in Africa.

Accepted Answer

Animals in Africa coevolved with humans, which is believed to have led to a more stable relationship between species, reducing the likelihood of extinctions that occurred on other continents where such coevolution did not happen.

Question 4

An organism whose decline or removal from a habitat causes many other species numbers to change dramatically is called __________ species.

Accepted Answer

A keystone species has a disproportional effect on the structure and function of an ecosystem. Their presence maintains the balance of the ecosystem, and their removal causes significant changes in the population of other species.

Question 5

Extinctions have occurred since life originated.However,since humans have been on Earth,many extinctions have occurred as a result of human activities.Biologists are concerned about this trend in extinctions and human presence.Which of the following choices is correct about how biologists estimate rates of extinctions?

Accepted Answer

Biologists estimate the number of extinctions by analyzing habitat loss and studying recorded extinction events. By studying the past extinction events and analyzing the current habitat loss, biologists can estimate the current rates of extinctions caused by human activities.

Question 6

Match the correct case study in conservation biology with its animal.

Accepted Answer

The case study of prairie chickens is often associated with the loss of genetic diversity due to habitat fragmentation and population decline, which led to reduced genetic variation and reproductive success.

Question 7

Regarding megafaunal extinctions,it is

Accepted Answer

The coevolution of African megafauna with humans is believed to have allowed them to develop survival strategies against human hunting, unlike in other continents where megafauna were not adapted to human presence.

Question 8

Edge effects are the result of which of the following?

Accepted Answer

Edge effects are the changes in temperature, humidity, light levels, and other environmental conditions that occur at the edge of a habitat due to habitat fragmentation or habitat shrinkage. As a result of these changes, the edge of the habitats increase in size, leading to edge effects. Population shifts or decreases are not the cause of edge effects, but can contribute to the overall impact on the habitat. Metapopulations may also be affected by edge effects, but they are not the direct cause.

Question 9

Areas with high levels of endemism are called species _________.

Accepted Answer

The term commonly used for areas with high levels of endemism is "hotspots". This term describes regions with high levels of species richness and endemism that are threatened by human activities, making them a priority for conservation efforts. Options A, B, and D do not accurately describe areas with high levels of endemism.

Question 10

Which of the following choices states a correct interpretation of this graph showing the relationship between extinction rate and island size?

Accepted Answer

The graph shows a negative correlation between island size and extinction rate. As the island size decreases, the extinction rate increases. Therefore, smaller islands have greater extinction rates than larger islands.

Question 11

Which of the following is a correct interpretation of this graph?

Accepted Answer

The answer of Which of the following is a correct...

Question 12

As habitats are fragmented,shrinking in size,a major problem is ______.

Accepted Answer

The edge effect refers to the negative impacts on the border or edges of fragmented habitats. These edges are more exposed to outside influences, such as predators or invasive species, and may experience changes in temperature, humidity, or vegetation. This can reduce the quality and quantity of resources available to the species living in these areas. Lack of corridors, overexploitation, and introduced species can also contribute to habitat fragmentation, but they do not directly address the issue of the edge effect.

Question 13

Sea otters have been used as an example of the "Keystone Species" concept.This means that sea otters

Accepted Answer

Sea otters are considered a keystone species because they have a significant impact on the structure and functioning of the kelp forest ecosystem. They are top predators that feed on sea urchins, which in turn prevents the overgrazing of kelp by sea urchins. Without sea otters, sea urchins populations can explode and decimate the kelp forests, leading to ecosystem collapse. The presence and actions of sea otters have a strong influence on maintaining the health and biodiversity of the kelp forest ecosystem.

Question 14

Animals that weigh more than 100 pounds are considered as

Accepted Answer

Animals that weigh more than 100 pounds are called megafauna. They are not necessarily endangered or extinct, but they are an important group of species that require conservation efforts to ensure their survival.

Question 15

A friend asks you for a definition of endemic because she is writing a history paper and this word keeps occurring in the literature in reference to bison on the Great Plains of the United States.Your response is that the word endemic means

Accepted Answer

Endemic refers to a species that is native or restricted to a particular geographic region or habitat and does not exist anywhere else in the world. In this context, bison on the Great Plains of the United States are endemic to that area.

Question 16

Species found in only one geographic area and nowhere else are _________ to that area.

Accepted Answer

Endemic species are specifically adapted to a particular geographic area and are found only in that area.

Question 17

__________ is the process of examining the genomes of animals and plants for useful genes.

Accepted Answer

Gene prospecting involves analyzing the genomes of organisms in order to identify and locate genes that may be useful for various applications, such as developing new medicines or improving crop yields. Genetic engineering involves manipulating and modifying genes for specific purposes, while phenotypic labeling involves tracking and labeling specific traits or characteristics in organisms. Cloning involves creating exact genetic copies of an organism.

Question 18

A scientist studied peregrine falcons to determine why the numbers of birds was declining.She determined that

Accepted Answer

The presence of DDT in the environment had a detrimental effect on the eggs being laid by the female peregrine falcons, causing the eggshells to be too thin, and ultimately contributing to the decline in their populations.

Question 19

Scientists estimate that about _____ of the world eukaryotic organisms have been discovered and given scientific names.

Accepted Answer

Scientists estimate that about 15% of the world's eukaryotic organisms have been discovered and given scientific names, indicating that a large majority remain unidentified.

Question 20

The majority of mammal and bird extinctions have occurred on ______.

Accepted Answer

Islands have a higher vulnerability to extinction due to their isolated nature and small size, making them more prone to habitat loss, invasive species, and other threats. Many bird and mammal species have gone extinct on islands.

Quiz 60: Conservation Biology