J Curve S Curve Essay Ch 40

Question 0

Type one survivorship curve in which does it apply

Answer 0

Flat at start reflecting low death rates during early and middle life then drops steeply as death rates increase among older age groups

Logistic growth model

Question 1

Survivorship curve

Answer 1

A plot of the proportion or numbers and a cohort still alive at each age

Question 2

What kind of animal apply in the type one survivorship curve

Answer 2

Many large mammals example humans

Question 3

Type III survivorship curve and in which does it apply

Answer 3

Drops sharply at start reflecting very high death rates for the young but flattens out as death rates decline for those few individuals that survive the early die off

Exponential growth model

Question 4

Organisms that apply to the type III survivorship curve

Answer 4

Long-lived plants fish marine invertebrates

Question 5

What is exponential growth

Answer 5

Population growth under ideal conditions access to abundant food and are free to reproduce their physiological capacity

Question 6

How was the J shaped curve formed

Answer 6

Population increasing a constant rate

Population grows more quickly when large rather than small

Question 7

When does the exponential growth model apply to organisms

Answer 7

Characteristic of some populations that are introduced into a new environment or who’s numbers were drastically reduced and are rebounding

Question 8

What is assumed in the exponential growth model

Answer 8

Resources are unlimited therefore caring capacity does not apply

Question 9

What is the logistic growth model

Answer 9

Per capita rate of increase approaches zero as the population size nears carrying capacity

Question 10

Describe the graph of the logistic growth model

Answer 10

Starts with exponential population growth then adds expression that reduces per capita rate of increase as population increases

Question 11

How does the logistic growth model achieve its sigmoid S shaped curve

Answer 11

New individuals added to the population most rapidly at intermediate population sizes when there is not only a breeding population of substantial size but also lots of available space and other resources

Question 12

Happens when the logistic growth model hits carrying capacity

Answer 12

Death rates increase and or birth rates decrease

Question 13

What causes populations to reach carrying capacity

Answer 13

Disease predation limited amounts of food and other resources

Question 14

What are the flaws with the logistic growth model

Answer 14

It assumes the populations adjust instantaneously to growth and approach caring capacity smoothly

Actually population will overshoe caring capacity

Question 15

K selection density dependent

Answer 15

Selection for traits that are sensitive to population density and or favored at high densities

Question 16

Where does K selection apply

Answer 16

Operate in populations living at a density near the limit imposed by their resources or caring capacity where competition is stronger

Logistic growth model S curve

Question 17

What are density dependent factors

Answer 17

Competition for resources
Toxic wastes
Territoriality
predation
Disease
Intrinsic factors

Question 18

R selection density independent

Answer 18

Selection for trades that maximize reproductive success in uncrowded environments

Question 19

Where does r selection occur

Answer 19

In environments in which population densities are well below caring capacity or individuals face little competition

Question 20

What does it mean for density independent when population size increases

Answer 20

Birthrates and a death rates do not change