Unit A: Section 4.0

Question 1

What is extinction?

Answer 1

Extinction is the disappearance of every individual of a species from then entire planet

Question 2

What percent of species do scientist think are extinct?

Answer 2

Scientists estimate that 99% of all the species that have ever existed are now extinct. Extinction is natural.

Question 3

What were most mass extinctions caused by?

Answer 3

Catastrophic events

Question 4

When was the last major environmental change?

Answer 4

1.8 million years ago, called the ice age

Question 5

What is extirpation?

Answer 5

Extirpation is a local extinction or the disappearance of a species from a particular area.

Question 6

What are endangered species?

Answer 6

Endangered species are ones that are in immediate danger of extinction or extirpation.

Question 7

What are threatened species?

Answer 7

Threatened species are likely to become endangered if their current declines are not reversed

Question 8

What are species of special concern?

Answer 8

Species that are of special concern are ones that are particularly vulnerable to natural events or human activities.

Question 9

Overspecialization

Answer 9

When organisms have adaptations that suit them to only a narrow set of environmental conditions.

Question 10

Why does overspecialization happen?

Answer 10

This probably happens because the environment that the organism inhabits remains unchanged for a very long time.

Question 11

What are the natural causes of extinction?

Answer 11

• catastrophic events such as volcanic eruptions, floods, or fires
• lack of food due to overpopulation
• disease

Question 12

Human causes of extinction and extirpation?

Answer 12

Habitat Destruction
Introduction of Non-Native Species
Over-Hunting

Question 13

Explain habitat destruction

Answer 13

Construction of buildings, agricultural development, logging, and the damming of rivers all change environments. These activities are necessary to meet human needs

Question 14

Explain introduction of a non-native species

Answer 14

When introduced species use the same resources as native species, they compete with the native species and cause the number of native species to decline, simply because there is less of everything.

Question 15

Explain Over-hunting

Answer 15

Over-hunting was the major cause of the decline and eventual extirpation and extinction. Basically when people killed certain species until they all died

Question 16

What are the effects of extinction and extirperation?

Answer 16

Reduced biological diversity. When an organism disappears locally or globally, many other species are affected.

Question 17

What is artificial selection?

Answer 17

Artificial selection is the process of selecting and breeding individuals with desirable traits to produce offspring that have these desired traits

Question 18

What is biotechnology?

Answer 18

The use of living things to make agricultural, industrial, or medicinal products

Question 19

What was a way people practiced biotechnology?

Answer 19

Native peoples practiced an early form of biotechnology when they gathered seeds from the biggest and healthiest corn plants

Question 20

What is a downside to biotechnology?

Answer 20

It takes a very long time generations

Question 21

How do farmers create plant clones?

Answer 21

The simplest way to create a clone is by taking a cutting from a plant and growing an identical plant from the cutting.

Question 22

Why would a farmer want to create a plant clone?

Answer 22

Because the plant has desirable traits

Question 23

What is the drawback to cloning plants?

Answer 23

The drawback is that this ideal plant has only so many leaves that can be cut off to use as cuttings.

Question 24

What way does scientist make clones?

Answer 24

They take cells from the desired plant and are placed in a Petri dish with all the chemicals needed. Once they develop into seedlings they are put in soil

Question 25

What is artificial reproductive technology?

Answer 25

It refers to any artificial method of joining a male and female gamete

Question 26

What are the 2 ways of artificial reproductive technology and explain both

Answer 26

Artificial insemination- When sperm is harvested and inserted into a female
In-vitro fertilization- Sperm and eggs are harvested and placed in a petri dish and fertilized. Then placed into cows

Question 27

Explain genetic engineering

Answer 27

Genetic engineering refers to any technology that directly alters the DNA of an organism. Takes a gene from one organism and implants it into another organism

Question 28

What some risks of cloning?

Answer 28

Unsuccessful pregnancies, birth defects, and deaths among clones.

Question 29

What are genetic engineering risks in plants?

Answer 29

The plants are able to breed with weeds and then become resistant to herbicides

Question 30

What are the strategies to conserve biological diversity?

Answer 30

Protected Areas
Restoration of Ecosystems and Species
Resource Use Policies
Controlling the Spread of Exotic Species

Question 31

What is in-situ conservation?

Answer 31

In-situ conservation refers to the maintenance of populations of wild organisms in their functioning ecosystems. Eg protected land

Question 32

What is ex-situ conservation?

Answer 32

Ex-situ conservation refers to the conservation of components of biological diversity outside of a natural habitat. eg. zoos