Population Ecology (Ch 46)

Question 1

What is the Biological Hierarchy?

Answer 1

Population; Species: Community; Ecosystem

Question 2

Define Ecology.

Answer 2

The study of the relationships of organisms to one another and to the environment.

Question 3

What did Thomas Malthus proposed in 1790?

Answer 3

The remarkable recent growth of the American population was a consequence of ample food supply and the active encouragement of marriages

Question 4

Define Population.

Answer 4

It consists of all the individuals of a given species that live and reproduce in a particular place.

Question 5

Define Species.

Answer 5

A group of individuals that can exchange genetic material through interbreeding to produce fertile offspring.

Question 6

Define Community.

Answer 6

A set of all populations found in a given place.

Question 7

Define Ecosystem.

Answer 7

A community of organisms and the physical environment it occupies.

Question 8

What are some characteristics of a population?

Answer 8

• Density and dispersion

- Factors affecting the growth and decline of populations.

Question 9

What is a Population Density?

Answer 9

A population’s size divided by its range.

Question 10

What is a Population Size?

Answer 10

It is simply the number of individuals of all ages alive at a particular time in a particular place.

Question 11

What is Demography?

Answer 11

The study of size, structure, and distribution of populations over time, including changes in response to birth, aging, migration, and death.

Question 12

What do we call a patchy distribution of populations?

Answer 12

Clumped population

Question 13

Some populations may go extinct; _____ may restore them

Answer 13

Migration

Question 14

Immigrate is to ___; _____ is to death

Answer 14

Born; Emigrate

Question 15

What are the different patches of habitat?

Answer 15

Control patch; small, isolated patches; small patches connected by corridor.

Question 16

The density of an organism is dependent on a number of factors, such as:

Answer 16

Food availability, nesting sites, and predators.

Question 17

How do we estimate population densities?

Answer 17

Quadrat and Transect

Question 18

What is a Quadrat?

Answer 18

Usually several areas that are counted

Question 19

What is a Transect?

Answer 19

A line across a habitat or part of a habitat.

Question 20

What is the Mark-Recapture Method?

Answer 20

It is commonly used to estimate an animal’s population size. A portion of the population is captured, marked, and released. Later, another portion is captured and the number of marked individuals within the sample is counted.

Question 21

Define Clumped Dispersal.

Answer 21

Individuals are clustered together.

Question 22

Define Uniform Dispersal.

Answer 22

Individuals are evenly spaced.

Question 23

Define cohort.

Answer 23

A group defined as the individuals born at a given time.

Question 24

Define Random Dispersal.

Answer 24

Individuals are randomly spaced.

Question 25

What are characteristics of r-strategists?

Answer 25

Species producing large numbers of offspring but provide few resources. They are Type III on the survivorship curve. i.e. Mouse, plants, trees

Question 26

What are characteristics of k-strategists?

Answer 26

Species producing few young but invest considerable resources. They are Type I on the susrvivorship curve. i.e. Humans, elephants, whales

Question 27

Name some factors that regulates population.

Answer 27

``` Predation Food availability Nesting area/Habitats Disease Pollution Natural Disasters ```

Question 28

What do the variables in the exponential growth equation represent? (G=rN)

Answer 28

G - Growth rate r - per capita rate of increase N - # of individuals @ the start of time

Question 29

Give examples of density-dependent factors.

Answer 29

Famine. These are factors where the effects on the size or growth of a population vary with the density of population itself.

Question 30

Give examples of density-independent factors.

Answer 30

These are weather based factors that strike populations without regard for the size of the population. Harsh. Really.

Question 31

What is an Island Biogeography theory and its 2 factors?

Answer 31

The theory states that the number of species that can occupy a habitat island depends on 2 factors: 1) The size of the island 2) The distance of the island from a source of colonists.