Chapter 21+23*

Question 1

Population Ecology

Answer 1

The study of a group of the same species living in the same geographical area.
It seeks to understand how populations change over time and space.

Question 2

Demographics of a Population

Answer 2

1. Population Size
2. Population Density
3. Rate of Growth
4. Distribution

Question 3

Population Density

Answer 3

How many people are in a unit area.

Question 4

Rate of Growth

Answer 4

Birth and Immigration

Deaths and Emigration

Question 5

Distribution

Answer 5

The spatial pattern of a population in a habitat.

Random, clumped, uniform, etc.

Question 6

2 Patters on Population Growth…

Answer 6

1. Exponential Growth (J-shaped)
   - Humans, Bacteria, and Invasive Species
2. Logistic Growth (S-shaped)
   - Nearly everything else

Question 7

Invasive Species

Answer 7

Species introduced to a habitat where they aren’t endemic.

Question 8

Carrying Capacity

Answer 8

The number of living organisms that an ecosystem can support.
Represented by “K”.
At K, the growth rate approaches 0 and many go negative.

Question 9

What limits population growth?

Answer 9

1. Density Dependent Factors

2. Density Independent Factors

Question 10

Density Dependent Factors

Answer 10

Factors that depend on the number of members of the population for availability.
EX: food, water, disease, predation.

Question 11

Density Independent Factors

Answer 11

Factors that don’t depend on the number of members.

EX: weather fire, natural disasters, accidents.

Question 12

Community Ecology

Answer 12

Seeks to understand complex interactions between many species in an area.
Community varies in size and complexity.

Question 13

Symbiosis

Answer 13

Interactions that species in a community develop.
Some interactions are harmful, some are neutral.
All interactions involve at least one individual being harmed or benefited.

Question 14

Commensalism

Answer 14

+ / 0
One species benefits at no cost to the other.
EX: Hitchhikers, Barnacles and Whales.

Question 15

Mutualism

Answer 15

+ / +
Both species benefit.
EX: Pollinators, Gut Bacteria.

Question 16

Exploitation

Answer 16

+ / -
One species benefits and the other is harmed.
EX: Parasitism (host isn’t killed), Predation(host killed).

Question 17

Competition

Answer 17

• / -
  An interaction where both species can be harmed.
  EX: Interspecies, Intraspecies.

Question 18

Interspecies

Answer 18

Resources/Space.

Different species.

Question 19

Intraspecies

Answer 19

Reproduction/Territory.

Same species.

Question 20

Biological Diversity

Answer 20

The variety of life forms on earth or supported by a given ecosystem.
Healthy ecosystems are immensely biodivese.
The more complex something is, the harder it is to destroy.

Question 21

Habitat

Answer 21

The physical environment where a species lives.

The space it occupies.

Question 22

Niche

Answer 22

The role a species plays in its environment.
What an organism does - its job.
EX: Predator, Prey, Producer.

Question 23

Competitive Exclusion Principle

Answer 23

When 2 species compete for the same niche only one can win.
No 2 species can occupy the same niche indefinitely.
Over time one species will become better adapted and out-compete the other.

Question 24

Niche Partitioning

Answer 24

The process by which natural selection drives competing species into different patterns of resource use.
Utilizing the same resource at a different time or in a different way.