Name

Class

Date

5.1 How Populations Grow Describing Populations For Questions 1–5 complete each statement by writing the correct word or words.

1. The

is the area in which a population lives.

2. Population density is the

of individuals per unit area.

3. How the individuals are spaced in their range is a population’s 4. Growth rate is how quickly a population __________________ 5. To find the of each age.

in size.

of a population, count the number of males and females

Population Growth For Questions 6–10, write True if the statement is true. If the statement is false, change the underlined word or words to make the statement true

6. If the death rate is less than the birthrate, the population is likely to shrink. 7. Immigration increases population size. 8. Young animals may immigrate from the place where they were born to establish new territories. 9. A high birthrate and immigration decrease population size. 10. Populations grow if more individuals are born than die in a period of time. 11. THINK VISUALLY The dots in the box represent individuals in a population with a random pattern of distribution. Use arrows and dots to show what will happen to this population if emigration is greater than immigration. (Assume birthrate and death rate are equal.) On the lines below, explain your drawing.

Exponential Growth 12. Describe the conditions in which exponential growth occurs.

13. Can exponential growth occur in a population of organisms that take a long time to reproduce? Why or why not?

14. Complete the graphs by drawing the characteristic shape of exponential population growth and the logistic growth in the correct place below.

15. When real-world populations of plants and animals are analyzed, why do they most often have the logistic growth curve?

16. What does the term carrying capacity refer to?

Apply the Big idea 17. What is an example of a limiting factor that humans use to control the carrying capacity of an environment for a particular type of organism? Explain your answer.

5.2 Limits to Growth Limiting Factors For Questions 1–6, write True if the statement is true. If the statement is false, change the underlined word to make the statement true

1. Limiting factors determine the immigration capacity of a population. 2. A limiting factor controls the growth of a population. 3. Limiting factors operate when growth is exponential. 4. Populations grow too large in the absence of limiting factors. 5. Competition is an example of a limiting factor. 6. Population size can be limited by factors such as predation.

Density-Dependent Limiting Factors 7. What is a density-dependent limiting factor? 8. When do density-dependent factors operate most strongly? 9. What are four density-dependent limiting factors?

10. What happened to the number of wolves on Isle Royale between 1975 and 1985? 11. What happened to the moose population when the number of wolves was low? 12. What is the relationship between the moose and the wolves on Isle Royale?

13. Is the number of moose on the island a density-dependent or density-independent limiting factor for the wolf? Explain your answer.

5.3 Human Population Growth Population Growth Population size is the number of individuals that make up a population. Immigration and births increase population size. Emigration and deaths decrease population size. The table below shows how different populations changed over a one-year time span. Follow the directions.

1. Study each population. Determine whether the overall population size has increased or decreased. 2. If the population size has increased, draw an arrow that points upward in the last column. 3. If the population size has decreased, draw an arrow that points downward. The first one has been done for you. Population

Births

Deaths

Number of People Who Emigrated

Number of People Who Immigrated

A

200

100

0

0

B

10

10

100

0

C

1

1

1

50

D

10

100

100

10

E

100

200

0

0

F

50

1

1

50

G

10

10

0

100

Population Size

Answer the questions.

4. Study population G. What would happen to the population size if 100 people emigrated?

5. A food shortage causes many members of a population to leave an area. What type of population movement does this describe? Circle the correct answer. emigration

immigration

6. What caused the population size of population C to increase?

.

Historical Overview Events in human history have affected the size of the human population. The table below lists some of these events. It shows the approximate size of the human population at the time of each event. Follow the directions.

1. Plot the data from the table on the graph. 2. Connect the points on the graph with a line. Event

Approximate Date

Human Population Size

Start of farming

8500 B.C.

0.1 billion

Use of plowing and irrigation

3400 B.C.

0.2 billion

Spread of bubonic plague

1300 A.D.

0.4 billion

Industrial Revolution

1800 A.D.

1 billion

Modern day

2000 A.D.

6 billion

Circle the correct answer.

3. Which term best describes the human population growth trend shown in the graph? exponential

logistic

4. After which event did the human population grow the most? bubonic plague

Industrial Revolution

Crossword Puzzle Complete the puzzle by entering the term that matches each numbered description. For two-word answers, leave a blank space between words. For an answer with a hyphen, include the hyphen.

Across

Down

1. a limiting factor that affects populations no matter what their size

2. the larger a population gets, the faster it grows

4. the number of males and females of each age in a population 7. moving out of the population’s range

3. a type of limiting factor that does not affect small, scattered populations very much

8. a growth pattern in which population size stabilizes at a maximum limit

5. the maximum number of individuals of a species that an environment can support

10. moving into a population’s range 11. a shift from high birthrates and death rates to low birthrates and death rates 12. the number of individuals per unit area

6. a factor that controls the growth of a population 9. the study of human populations