chapter 5 - populations photo credit:
TRANSCRIPT
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