Interactions in Ecosystems

Question 1

What is resource availability’s role in a community?

Answer 1

Gives structure to a community and allows species to share habitats and resources.

Remember- enough to go around for

Question 2

What is competition in ecological terms?

Answer 2

Occurs when two species use resources in the same way.

Question 3

What is competitive exclusion?

Answer 3

Keeps two species from occupying the same niche, leading to:
* One species being better suited and pushing the other out or causing extinction.

Remember- one will be EXCLUDED from their job because they suck at it

Question 4

What is an ecological niche?

(Niche- job sorta assigned to the organism)

Answer 4

Includes all of the factors that a species needs to survive, stay healthy, and reproduce:
* food
* abiotic conditions
* behavior

Every organism has a habitat and a niche.

Question 5

What is the relationship between competitive exclusion and divergent evolution?

Answer 5

The two species will further diverge due to evolution.

Remember- they can lead to niche separation and reduced competition.

Question 6

Define habitat.

Answer 6

All aspects of the area in which an organism lives, including:
* biotic factors
* abiotic factors

Habitat and niche are distinct but interrelated concepts.

Question 7

What is interspecific competition?

Answer 7

When two different species compete for a limited resource.

Remember- diff(E)r(E)nt and int(E)rspecific

Question 8

What is intraspecific competition?

Answer 8

When the same species struggle against one another for the same limited resource.

Remember- s(A)me and intr(A)specific,

Question 9

Define niche partitioning.

Answer 9

The division of a niche between species to reduce competition.

Remember- they just PART(itioning) ways and divide up their jobs so they don’t start competiting with eachother again.

Question 10

What is symbiosis?

Answer 10

A close and often long term interaction between two or more different biological species.

Remember- symbio(SIS), looks like SISter. Sisters are usually close, bonded.

Question 11

Name the three major types of symbiotic relationships.

Answer 11

1. Mutualism
2. Commensalism
3. Parasitism

Question 12

What is mutualism?

Answer 12

A type of symbiotic relationship where both organisms benefit.

(Remember: mutual, mutuals are buddies YAY!)

Question 13

What is commensalism?

Answer 13

A type of symbiotic relationship where one organism benefits and the other is unharmed.

Remember: co (together), men (think of it as mean), they’re working together but only one gets the good stuff but atleast the other isn’t affected! Yay?

Question 14

What is parasitism?

Answer 14

A type of symbiotic relationship where one organism benefits and the other is harmed.

Remember: Parasit (think of parasites) they’re bad, this is the bad one, one gets harmed. Nay!

Question 15

What does population dispersion refer to?

Answer 15

How a population is spread in an area.

Remember- di(SPER)sion and (SPRE)ad

Question 16

What are the three types of population dispersion?

Answer 16

1. Clumped Dispersion
2. Uniform Dispersion
3. Random Dispersion

Question 17

What is clumped dispersion?

Answer 17

Living close together

Remember- CLUMPED (close) together. They’re like compiled on top of eachother if that helps you remember :)

Question 18

What is uniform dispersion ?

Answer 18

Living at specific distances from on another

Remember- when you think of a uniform think of the army. They’re typical lined up UNIFORMLY!

Question 19

What is random dispersion?

Answer 19

Indivduals spead randomly

This one is self explanatory..

Question 20

What is logistic growth?

Answer 20

Population growth but it levels due to facing limited resources.

Remember- (L)ogistic, (L)imited

Question 21

What is population density?

Answer 21

A measurement of the number of individuals living in a defined space. (# of individuals/area (units^2)= population density)

Question 22

What are the two types of limiting factors?

Answer 22

1. Density dependent
2. Density independent

Question 23

Define density dependent limiting factors.

Answer 23

Factors affected by the number of individuals in a given area, such as:
* predation
* competition
* parasitism and disease

Question 24

Define density independent limiting factors.

Answer 24

Factors that limit a population’s growth regardless of density, such as:
* unusual weather
* natural disasters
* human activities

Question 25

Name the **three** types of **survivorship** **curves**.

Answer 25

1. **Type I** 2. **Type II** 3. **Type III**

Question 26

What is a **survivorship** **curve**?

Answer 26

A **diagram** showing the **number** of **surviving** members over time from a **measured** set of **births**.

Question 27

What **characterizes** **Type I** survivorship curves?

Answer 27

**Low** level of **infant** **mortality** and an **older** **population**, **common** to **large** **mammals** and humans.

Question 28

What **characterizes Type II** survivorship curves?

Answer 28

Survivorship rate is **equal** at **all** stages of **life**, **common** to **birds** and **reptiles**.

Question 29

What **characterizes** **Type III** survivorship curves?

Answer 29

Very **high** **birth** rate and very **high** **infant** **mortality**, **common** to **invertebrates** and **plants**.

Question 30

What **factors** determine **changes** in a **population**’s **size**?

Answer 30

1. **Immigration** 2. **Births** 3. **Emigration** 4. **Deaths** ## Footnote Remember: Immigration is going in, emigration is exiting.

Question 31

What is **carrying** **capacity**?

Answer 31

The **maximum** number of **individuals** in a **population** that the **environment** can **support**.

Question 32

What is **exponential** **growth**?

Answer 32

A **rapid** **population** **increase** due to an **abundance** of **resources**.

Question 33

What are **limiting** **factors**?

Answer 33

**Elements** that keep the **size** of a population **down**.

Question 34

What is **ecological succession**?

Answer 34

A process of **change** in the **species** that **make up a community**.

Question 35

What initiates **primary** **succession**?

Answer 35

Started by **pioneer** **species** to **break** down hard **rock** or **ground** into **soil**.

Question 36

Give examples of **pioneer species**.

Answer 36

1. **Lichens** 2. **Mosses** 3. **Fungi** 4. **Weeds**

Question 37

What initiates **secondary** **succession**?

Answer 37

**Started** by **remaining** **species** to reestablish the **damaged** **ecosystem** where **soil** was left **intact**.

Question 38

Give **examples** of disturbances that can lead to **secondary succession**.

Answer 38

1. **Fire** 2. **Floods** 3. **Tornados**

Question 39

What are **nonnative** **species**/**introduced** **species**?

Answer 39

They **enter** an area and they **grow** exponentially due to **abundance** of **food**, **space**, and **no** **predators**.