POPULATIONSL A S T U N I T ! ! ! ! WA H O O O O ! ! !

OBJECTIVES:

- Describe the factors that affect the carrying capacity of the environment.

- Explain how change in population density is affected by emigration, immigration, birth rate and death rate, and relate these factors to the exponential growth of human populations.

- Explain how technological advances have affected the size and growth rate of human populations throughout history.

GRAPH #1 EXPONENTIAL GROWTH

• Exponential is growth that would take place under ideal conditions with unlimited resources.

GRAPH #2: LOGISTICAL GROWTH

• Logistical is growth that is eventually limited to a number (carrying capacity) that can be supported by environmental resources.

• Carrying Capacity:

The number of individuals in a population that an environment can support.

Logistical Growth Curve

Exponential Growth Curve

DENSITY DEPENDENT VS. DENSITY INDEPENDENT

• Logistical growth is affected by DENSITY DEPENDENT factors. These are things that affect the population as it gets more and more dense…

For example:Running out of foodRunning out of places to liveOther limited resourcesSpread of disease

• DENSITY INDEPENDENT factors = things that affect the population no matter if it is large or small. For example, a hurricane.

WHAT TYPE OF POPULATION GROWTH HAS THE HUMAN POPULATION

EXPERIENCED?

How did we get so big so fast???

FACTORS THAT AFFECT GROWTH

1. Birth Rate: the amount of births for a given time period

2. Death Rate: the amount of deaths for a given time period

3. Immigration: movement of organisms INTO an area occupied by an existing population

4. Emigration: movement of organisms OUT of an area where population is located

AGE STRUCTURE DIAGRAMS

A graph that shows a population’s growth based on AGE and GENDER.

Age Groups:1. Pre-Reproductive= 0-4 through

15-192. Reproductive= 20-24 through 40-

443. Post Reproductive= 45-49

through 80+

There are 3 types of growth patterns:1. Rapid Positive Growth2. Slow Positive Growth 3. Negative Growth

RAPID POSITIVE GROWTH

SLOW POSITIVE GROWTH

NEGATIVE GROWTH

YEAST POPULATION LABS

After reviewing her data, the student decides to perform an additional trail at 35°C. She observes that the balloon inflates faster than during the trail in which the 30°C water was used. This additional trial supports which of the following hypotheses?

a) The optimum temperature for yeast fermentation is less than 35°Cb) Warmer temperatures are more favorable for yeast fermentationc) Yeast require less sugar when maintained at lower temperaturesd) The time required for fermentation increases with increasing temperature

The yeast were placed on a nutrient dish and allowed to grow. On which day was additional nutrient most likely added to the yeast culture?

a) 3b) 4c) 6d) 7