chapter 44

Question 1

What is a population?

Answer 1

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

Question 2

Ecology

Answer 2

Is the study of the relationships of organisms to one another ( the biotic components and the environment (the abiotic components)

Question 3

What is closely intertwined?

Answer 3

Ecology and Evolution

Question 4

What is a collection o individuals of the same species is called ?

Answer 4

A population

Question 5

A collection of populations makes a ?

Answer 5

community

Question 6

A community with the habitat makes an

Answer 6

ecosystem.

Question 7

What are the key characteristics of populations ?

Answer 7

Size = headcount, Range = space occupied
Density = size/range

Question 8

Distribution

Answer 8

of indivduals within polations Sessile, or sedentary, organisms can be counted within a defined area, and total populatiom can be extrapolated from that count, Mark and recapture is useful for counting mobile organisms.

Question 9

What is mark and Recapture?

Answer 9

an extrapolation method
Population size (N)
Butterflies caught on the first day ( M = 100)
Marked and unmarked on the second day (C = 120)
Recaptures (R = 30)
N= C/R X M
N= 120/30 x 100 =400

Question 11

what does population size do over time?

Answer 11

Increase or decrease

Question 12

What affects population size?

Answer 12

Immigration, Emigration, death and birth
Morality and Emigration decreases population.

Question 13

Population Growth equation

Answer 13

N= N2-N1=(B-D) +( I-E)

Question 14

Logistic Growth

Answer 14

Limiting factors keep growth in check - hence a “carrying capacity” for each species in each space in each time - the K

Question 15

Density - Independent Factors ( pop does not matter)

Answer 15

• limit population regardless of population density
• Droughts or other severe events
• Environmental conditions (temperature, light availability)

Question 16

Density- Dependent factors (pop’n size does not matter)

Answer 16

• competition for limited resources
• Predation, parasitism
• Diseases

Question 17

Density-dependent Effects

Answer 17

Carrying Capacity (k)

Question 18

K is always what specific?

Answer 18

species-specific, time- specific and location-specific

Question 19

What helps ecologists understand past changes and predict future changes in population size?

Answer 19

The age structure of a population

Question 20

Population Demography

Answer 20

Population ecologists use demography- the study of statistics such as birth rates ,age or size structure and distribution over time and environments

Question 21

The pattern of investment in growth vs. reproduction vs. survival over an organism’s lifetime is called?

Answer 21

Life history

Question 22

Why care about the age structure?

Answer 22

Survival and mortality vary across age classes.

Question 23

Survivorship curves show?

Answer 23

How survival or morality rate change with age.

Question 24

Type I Survivorship

Answer 24

mortality rate increases later in life ( large animal (bears , humans and dogs)
- annual plants ( most seedlings survive to reproduce)

Question 25

Type II survivorship

Answer 25

Mortality rate is constant over life Plants competing for limited space which (self- thin) , birds, reptiles

Question 26

Type III Survivorship

Answer 26

Mortality rate is highest in the young, insects and marine organisms with tiny dispersing larvae and most tree.

Question 27

Reproduction is

Answer 27

distributed over a schedule
- Repeated reproduction over lifetime is iteroparity
-Semelparity is single reproductive event then death
TRADE OFF

Question 28

what patterns reflect predictability of environment?

Answer 28

REproductive patterns

Question 29

what are the two models of reproductive mode?

Answer 29

r-strategy and K strategy