Ch 8-9Population Chages & Interactions

Question 0

Population size

Answer 0

The number of organisms

Question 1

Populations of organisms are……

Answer 1

Dynamic.

Can assess the health of animals or entire species

Question 2

Population density

Answer 2

Calculated by dividing the number of organisms (n) by the total area (A) or total volume (V)

Question 3

Population distributions

Answer 3

Clumped dispersion
Uniform dispersion
Random dispersion

Question 4

Factors that affect population change

Answer 4

Only 4

1. Natality - # of births
2. Mortality - # of deaths
3. Immigration - “in” move in
4. Emigration - “exit” move out

Question 5

Growth rate:

Gr

Answer 5

Describes how quickly a population is increasing or decreasing

Gr =

Question 6

Per capita growth rate:

cGr

Answer 6

Represents the change in a populations size relative to the initial population size.

cGr=

Question 7

Population growth models

Answer 7

• open population
• closed population
• exponential growth
• environmental resistance
• biotic potential
• density ~dependent factors
• density ~independent factors
• intra~specific competition
• inter~specific competition

Question 8

Open population

Answer 8

Allows things to enter and leave

Question 9

Closed population

Answer 9

Does not allow things to enter or leave

Question 10

Exponential growth

Answer 10

Size increases as a fixed rate per time

Question 11

Environmental resistance

Answer 11

Any factor limiting a populations ability to reach it’s biotic potential.

Question 12

Biotic potential

Answer 12

Maximum # of offspring a species could produce with unlimited resources

Question 13

2 types of growth curves that show population growth.

Answer 13

J-shaped

S-shaped

Question 14

4 phases of growth curves (J-shaped & S-shaped)

Answer 14

1. Lag phase
2. Growth phase
3. Stationary phase
4. Death phase

Question 15

Density-dependent factors

Answer 15

Influences a population due to its density.

Ex. Disease or predators

Question 16

Density-independent factors

Answer 16

Influences a population regardless of density.

Ex. Fire or flood

Question 17

Intra-specific competition

Answer 17

Interaction between the same species.

Duck&Duck

Question 18

Inter-specific competition

Answer 18

Interaction between different species.

Duck&geese

Question 19

K-selected strategy

Answer 19

Few offspring, more parietal care
Usually larger, longer life span

Elk, elephants, humans

S-shaped curve

Question 20

R-selected strategy

Answer 20

Many offspring, little to no parental care
Usually smaller, short life span.

Mosquito

Question 21

Predator prey cycles

Answer 21

Mimicry

Camouflage

Question 22

Symbiosis

3types

Answer 22

A relationship in which organisms of two different species live in close, usually physical contact.

• Parasitism
• Commensalism
• Mutualism

Question 23

Parasitism

Answer 23

One benefits and the other is harmed

Question 24

Commensalism

Answer 24

One benefits and the other doesn’t care

Question 25

Mutualism

Answer 25

Both organisms benefit

Question 26

Succession:

2types

Answer 26

the slow replacement of one community of plants by another.

Primary succession
Secondary succession

Question 27

Primary succession

Answer 27

• Plants take over an area not previously covers by plants.

- due to the lack of nutrients

Question 28

Secondary succession

Answer 28

• Plants take over an area that was pervious lay covers by plants.
• faster due to availability of nutrients.

Question 29

Pioneer community

Answer 29

• first plants to arrive during succession…

- weeds

Question 30

Climax community

Answer 30

These are the last plants to arrive