Chapter 5 - Populations

Photo Credit: http://www.flickr.com/photos/solidether/1084349065/

5-1 How Populations Grow

Geographic distribution – the area a pop lives(range)

Population Density – the number of individuals in an area

Population Growth

●Number of births●Number of deaths●Emigration (out) & Immigration (in)

In Springfield, 45 babies are born in the year 2008. 15 people died that same year. What is the growth rate for the city?

Positive Growth rate

= increase

Negative Growth rate = decrease

Exponential Growth –reproduction at a constant rate. - occurs under ideal conditions (no limits) - J-shape curve

Logistic Growth – resources become less available, growth slows or stops- S-shaped curve

Carrying Capacity – the number an environment can support

You are having a party.How can you figure out the carrying

capacity of your party.

Factors:

5-2 Limits to Growth

Limiting Factor – causes population growth to decrease

Density-Dependent Factors

– population size--competition --predation--disease

Density-Independent Factors – does not depend on population size

-Unusual weather-Natural disasters-Some human activities

Predator - Prey Relationship

- predators control populations- as the prey numbers increase, so do predators

Prey will always outnumber predators!

Quick check.

1. The area where a population live is called:a) population density b) geographic distributionc) carrying capacity

2. The graph shows why type of curve? a) exponential b) logistic

3. The arrow indicates the: a) limiting factor

b) density dependentc) carrying capacity

4. What is the number of deer that can be supported by the island? a) 90-96 b) 75-80 c) 10 -30

5. What information is needed to determine the population growth rate?a) birth rate b) death rate c) number of immigrants d) all of these

6. A flood causes a 30% reduction in the population of crocodiles. This is considered a:a) density independent factorb) density dependent factorc) logistic growth factor

7) If an area is a negative rate of population growth, then the population is:a) increasing b) declining c) extinct

8) Population density refers to:a) the number of individuals in an area b) the total number of individuals in a species

DEMOGRAPHY

- the study of human population growth - explains how populations change over time.

Detroit

Demographic Transition – a dramatic change in birth and death rates

-U.S., Japan, and Europe population growth has stopped

ZERO POPULATION GROWTH

In order to achieve ZPG, each couple has only 2 children.

AGE STRUCTURE DIAGRAMS

Show percentage of people alive at each age group

Which diagram above is: 1. A country where the king orders the deaths of all the baby boys 2. A country at war, many young men die in that war3. A country with poor health care for women, many die in childbirth4. A country where AIDS kills people in their 30s

AB

CD

THIS POWERPOINT TAKEN FROMhttp://www.biologycorner.com/bio2/notes_populations.html