AP ENVIRONMENTAL: POPULATIONS, UNIT 4

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R strategists have ____ maturation, have ____ offspring, are _____ in size, have ____ care for young, and have a ____ lifespan.

Rapid, many, smaller, little, shorter

Two examples of R strategists are

Mice & fish

K strategists have ____ maturation, have ____ offspring, are _____ in size, have ____ care for young, and have a ____ lifespan.

Slow, few, larger, more, long

Two examples of k strategists are

Lion & elephant

What are some factors that influence a population?

Births, deaths, and resources

What is population size?

The total number of organisms in a given area

What is population density?

The total number of organisms per unit area.

What is population dispersion?

The arrangement of organsims in an area

The three types of population dispersion are

Clumped/group, uniform/equal, & random

Why are most populations arranged in clumped?

Resource availability, caring for young, protection, mating, group work

What factors affect population growth?

Birth, death, immigration, emmigration

What is the formula to calculate growth rates? (Formula #1)

(Birth + immigration) - (death + emmigration)

What is the formula for natural growth? (Formula #2)

Birth - death

What is the formula to calculate crude birth/death rates? (Formula #3)

[(The number of Births/deaths)/total population] x 1000

What are crude birth/death rates?

The number of birth/deaths per 1000 people in one year.

The rule of 70 formula estimates the number of years it takes for

A certain variable to double

What is the formula for the rule of 70? (Formula #4)

T=70/r

The variable “t” in the formula of rule of 70 is

Doubling time

The variable “r” in the rule of 70 formula is

Annual growth rate [note; never convert percentage into a number. 7.31% becomes 7.31)

Fertility rates are

The number of children a woman will have in her lifetime

Total fertility rate is

The average number of children born to a woman in reproductive years/in her lifetimr

Replacement level fertility rate is

The average number of children a couple must have to replace themselves

Populations cannot grow indefinitely due to

Environmental resistance

Biotic potential is

Population growth with no limits

Biotic potential results in ____ growth.

Exponential

Carrying capacity (k) is

The maximum amount of species in a ecosystem that can be supported by the environment

Carrying capacity is determined by ____ and ____

Biotic potential & environmental resistance

Intrinisc growth & logistic growth graphs both deal with

Population growth over time

When a population meets environmental resistance, it results in a ____ population

Stabilizing/fluctuating

Intrinsic growth graphs represent ____ niches. The ____ shaped curve shows the rate at which a population would grow with ______ _____

Fundamental, J-shaped, unlimited resources/no environmental resistance

Logistic growth graphs are ___ shaped and represent the rate at which ______

S-shaped, population growth decreases as it reaches the carrying capacity

What conditions would cause line #1 to have this pattern?

Climate change/seasons

What conditions would cause the protrusion in line 4?

Immigration or a baby boom

Would the carrying capacity of line 3 be at the highest point of the line? Why or why not?

No. The carrying capacity would not be at the highest point in line 3 because it’s not relatively stable at that level.

Density-dependent limiting factors of a population are

Resources, predation/competition, & disease

Density-independent limiting factors of a population are

Natural disasters, clearing of habitats, pesticides, weather, war, & temperature

Developing countries (LDC), with lower income and weak social support systems, have ____ economies & ____ population growth.

Agriculture, rapid

Developed countries (MDC) have higher incomes and strong social support systems, which leads to a(n) ______ economy and ____ population growth.

Industrial, slower

The world population is growing exponentially. The three most populared countries are

China, India, & USA

Some plausible reasons for population growth are

Expanding habitats, beginning an agricultural society, food availability, & germ theory (discovery of medicine)

Birth rates are currently decreasing due to

Urbanization, women studying and working, birth control, the cost of raising children, & religious/cultural beliefs (note: religious/cultural beliefs can go either way)

Birth rates can increase because of

Children in the workplace, pension opportunities, & religious/cultural beliefs (sometimes)

How are death rates AND birth rates decreasing?

People are living longer lives & because of the amount of people, there is usually a replacement.

Factors that influence death rates are

An increase in life expectancy (because of medical advances), decrease in infant death rates, increased food supply/improved nutrition & improved hygiene

Type 1 of the survivorship curve shows

A high probability of surviving adulthood up to a certain age

Type 2 of the survivorship curve shows

The chance of survival/death is independent of age

Type 3 of the survivorship curve shows

A high probability of death in early stages but those that survive live very long

Line 1 in this graph could be a species like

Birds

What type of survivorship curve is represented by line 3?

Type 1

What type of survivorship curve is represented by line 2?

Type 2

Factors that affect migration are

Economy, war, environmental refugeeing, political freedoms, & religious freedoms

Age structure diagrams show the distribution of ages in a specific population at a certain time. How are they usually split?

0-14 is pre-reproductive, 15-44 is reproductive, 45-85+ is post reproductive

An age structure diagram showing rapid growth is best represented by

Developing countries with people with short lifespans

Between rapid and slow growth, there is an increase in

Life expectancy

The 4 most popular types of age structure diagrams are

Rapid, slow, stable, & declining

Demographic transition models usually have 4 or 6 phases. These models examine _______ & _____ rates to calculate and hypothesize _________

Birth & death rates, population growth changes

Stage 1 of the demographic transition model is pre-industrial. Population growth is _____. The birth rate (BR) is ____ and death rate is _____. Explain why for both cases.

Population growth is net zero/low in growth. Birth rates are high due to no birth control and high infant morality and death rates are high due to the lack of medicine/resources

Stage 2 of the demographic transition model is transitional. The population growth is _____. The birth rate (BR) is ____ and death rate is _____. Explain why if there was a change from the prior stage.

Population growth is exponential. Birth rates remain high. Death rates drop because life expectancy increased, we settled, resources are easier to access, and better hygiene

Stage 3 of the demographic transition model is industrial. The population growth is _____. The birth rate (BR) is ____ and death rate is _____. Explain why if there was a change from the prior stage.

Population growth stays exponential. Death rates continue to drop (continous increase of resources, medicine, & hygiene). Birth rates rapidly decrease because women go to work

Stage 4 of the demographic transition model is post-industrial (it can also be whatever is after stage 3). The population growth is _____. The birth rate (BR) is ____ and death rate is _____. Explain why if there was a change from the prior stage.

Population growth is still increasing but starts to stabilize. The birth and death rates are both steady and low.

If birth & death rates are low, why is the population still growing?

There are still enough people in pre-reproductive/reproductive years alive.

We can slow population growth through… (5 ways)

Family planning, empowering women (w/ education & jobs), free access to contraceptives/abortions, late marriages & encouraging families to not have more than one child

In 1974, there was 12,500 births in Miami with a population of 70,000. What is the crude birth rate? (Round to nearest whole number)

179

In 2016, the world population growth is about 2.9% per year. How long would it take for this world’s population to double & by what year would this doubling occur? (Round to the nearest whole number)

24 years, 2040

If the doubling time for the world’s population is 23 years, what will be the growth rate over this time period? (Round to nearest hundreth)

3.04%