2.2 Study Guide

Question 1

How does birth, death, immigration, and emigration each affect pop growth.

Answer 1

Birth: more births means more population
Death: decreases population so lowers is, counteracts birth
Emigration: things exiting the ecosystem, leaving, decreases the growth rate
Immigration: things entering the ecosystem, counteracts emigration

Question 2

What does a Logistic graph look like?

Answer 2

Have a (K) maximum cap point
Curve that can go up or down, but normally shouldn’t go past the cap

Question 3

What does an Exponential graph look like?

Answer 3

line increasing, shouldn’t have a cap or significant steady curve like logistic does.

Question 4

What do variables N, N0, r, t, K, dN/dt stand for?

Answer 4

N= total pop.
No= initial pop size
r; max per capita growth rate
t= time
K= carrying capacity
dN/dt= pop growth rate

Question 5

What do Density-dependent factors mean and examples?

Answer 5

Factors that affect population based on the density

Ex. disease, social behavior

Question 6

What do Density-independent factors mean and examples?

Answer 6

Factors that affect the population are not based on the density.

Ex. Abiotic, sunlight, drought

Question 7

What happens in a logistic graph when K is increased?

Answer 7

N can go up

Question 8

What happens in a logistic graph when r is increased?

Answer 8

The population decreases

Question 9

What happens when you increase N?

Answer 9

R goes down, pop. gets bigger, nears K