Week 3 learning Objectives

Question 1

What are population demographics?

Answer 1

The size, age structure, and changes in a population over time.

Question 2

What is a density dependent population growth method?

Answer 2

This method is applied to display the maximum attainable density that incorporates constraints to a population growth.

Question 3

What is a density independent population growth method?

Answer 3

A simple method that assumes the population is not constrained by limiting factors

Question 4

What are the main limits to populations in time and space

Answer 4

Environmental limiting factors (Abiotic) - Biological interaction limiting factors (Biotic)

Question 5

What are some environmental limiting factors?

Answer 5

Physical changes: Temperatures - water - natural disasters - landscape changes (Abiotic).
Availability of suitable habitats (Mainly reproduction)

Question 6

What are some Biological interaction limiting factors?

Answer 6

Food supply - Abundance/Distribution of predators - Diseases - Other species - Life expectancy

Question 7

What is the body size to population density equation

Answer 7

Log(population density) = a + b x log(body weight)

Question 8

How can habitat limitation effect population size?

Answer 8

A reduction in reproductive habitats with have a large impact on population size, resulting in a decrease or increase in a populations size

Question 9

How does the interaction of pray and predators effect population size?

Answer 9

A reduction in predators will allow pray species populations to exponential grow until they reach their carrying capacity. Example, Red kangaroos and dingos.

Question 10

What limiting factor plays the largest role in ecosystems?

Answer 10

Humans activities

Question 11

What is a demography?

Answer 11

Size and structure of populations and changes with in populations

Question 12

Why is it important to understand the age structure of a organism?

Answer 12

Age structures will give you the life expectancy of the organism, and this directly effects populations size and growth

Question 13

What is r selected reproduction

Answer 13

The all or nothing approach. Low maternal care, while producing large amounts of offspring in hopes some will survive

Question 14

What is K selected reproduction

Answer 14

Few young, high care approach. High maternal/parental care, allowing for the offspring to have a greater chance of survival.

Question 15

What are the 2 keys drivers that changes population

Answer 15

Survival and mortality.

Question 16

What significant data is recorded in life data?

Answer 16

Mortality/Survivor-ship - Age structure - Number of individuals at a set age.

Question 17

What are the assumptions of exponential growth?

Answer 17

Must be a closed population - No constraints in growth

Question 18

What is density-independent growth?

Answer 18

Organisms within an environment that have unlimited resources - no competitors or predators, and will keep increasing will no limit (Exponential)

Question 19

What is density-dependent growth?

Answer 19

Accounts for the ‘upper limit’ to the population growth.
As population size increases beyond a ‘certain point’
Birth rates decrease and/or death rates increase (Logistic)

Question 20

What happens when a population approaches the carrying capacity (K)

Answer 20

As the population gets close to a carry capacity the rate of increase in the population will slow down

Question 21

What is symbiosis?

Answer 21

Interactions between two different organisms living in close physical association, typically to the advantage of both

Question 22

What is commesalism?

Answer 22

One species benefits from the relationship and the other is not harmed-(This relationship can change over time)

Question 23

What is mutualism?

Answer 23

Both organisms benefits from the relationship with nether being harmed

Question 24

What are sub-categories of mutualism

Answer 24

Obligate mutualism and Faculative mutualism

Question 25

What is Obligate mutualism

Answer 25

Interacting species depend of each other and one cannot survive without the partner

Question 26

What is faculative mutualism

Answer 26

Interacting species are found together or independently, but populations perform better when together than alone

Question 27

What are the benefits and costs form obligate mutualism

Answer 27

Benefits = Nutrients, habitat protection
Cost = Dispersal is limited by the other species/survival.
If one dies they both die = Extinction