2.2 Study Guild

Question 1

How is population growth determined from birth?

Answer 1

The rate of natural increase is the difference between birth and death rates.

Question 2

How is population growth determined from death?

Answer 2

The rate of natural increase is the difference between birth and death rates.

Question 3

How is population growth determined from emigration?

Answer 3

The formula for population growth rate is r = (b i) - (d e), where r is the growth rate, b is the birth rate, i is the immigration rate, d is the death rate, and e is the emigration rate.

Question 4

How is population growth determined from immigration?

Answer 4

The formula for population growth rate is r = (b i) - (d e), where r is the growth rate, b is the birth rate, i is the immigration rate, d is the death rate, and e is the emigration rate.

Question 5

How does one sketch basic graphs showing exponential growth?

Answer 5

1. Create a table of points.
2. Plot at least 3 point from the table including the y-intercept (0,1) .
3. Draw a smooth curve through the points.
4. State the domain, (−∞,∞) , the range, (0,∞) , and the horizontal asymptote, y=0 .

Question 6

How does one sketch basic graphs showing logistic growth?

Answer 6

1.- Label the x-axis as “Time” or “Generations” and the y-axis as “Population Size.”
2. Plot an exponential growth curve, starting at low initial population size and rising steeply upward. This curve represents unrestricted growth with no limiting factors.
- Label this curve as “Exponential Growth.”
3. Draw a horizontal line across the graph, parallel to the x-axis. This line represents the carrying capacity (K), which is the maximum population size that the environment can sustain indefinitely.
- Label this line as “Carrying Capacity (K).”
4. Plot a logistic growth curve, starting similarly to the exponential growth curve but eventually leveling off near the carrying capacity line.
- The logistic growth curve should rise steeply initially, then gradually flatten out as it approaches the carrying capacity line.
- Label this curve as “Logistic Growth.”
5. - Shade the area under the exponential growth curve to represent the region where exponential growth occurs. This area extends from the start of the curve to the point where it intersects the carrying capacity line.
- Label this shaded area as “Exponential Growth Area.”
6. - Add appropriate labels to the x-axis (time or generations) and the y-axis (population size).
- Title your graph, for example, “Comparison of Exponential and Logistic Growth Models.”
- Include a legend if necessary to distinguish between the exponential growth and logistic growth curves.

Question 7

Where population growth is highest in logistic growth?

Answer 7

When a population reaches its carrying capacity ,K.

Question 7

Where population growth is highest in exponential growth?

Answer 7

During exponential growth, a population always grows at its maximum per capita rate.

Question 8

What does the variable N stand for in the growth models?

Answer 8

Population size.

Question 9

What does the variable N0 stand for in the growth models?

Answer 9

Original Population size

Question 10

What does the variable r stand for in the growth models?

Answer 10

Per capita rate or per individual.

Question 11

What does the variable t stand for in the growth models?

Answer 11

time

Question 12

What does the variable K stand for in the growth models?

Answer 12

carrying capacity

Question 13

What does the variable dN/dt stand for in the growth models?

Answer 13

the population growth rate.

Question 14

What is the definition of Density Dependent?

Answer 14

Change in the birth and death rate of a population as a result of changes in population density;

Question 15

What is the definition of Density independent?

Answer 15

Any force that affects the size of a population of living things regardless of the density of the population

Question 16

Are Density Dependent variables mostly abiotic or biotic?

Answer 16

biotic

Question 17

Are Density Independent variables mostly abiotic or biotic?

Answer 17

abiotic

Question 18

Examples of Density Dependent variables.

Answer 18

disease, completion for water

Question 19

Examples of Density Independent variables.

Answer 19

flood, drought

Question 20

How exponential and logistic growth models change when r change and why?

Answer 20

When r is changed in an exponential growth model the population size increases because the number of individuals per area increase. When r is changed in a logistical model the population increases as more individuals can fit in one area.

Question 21

How exponential and logistic growth models change when N change and why?

Answer 21

The population growth rate in the exponential growth model also increases without limit because of the lack of completion or limiting factors, but it decreases as N nears the carrying capacity in the logistic growth model due to the limiting factors and competition.

Question 22

How exponential and logistic growth models change when K changes and why?

Answer 22

If K changes in an exponential growth model then the population will grow faster or slower with increasing or decreasing limiting factors. . If k changes in a logistical growth model then the population will increase or decrease with k due to the limits it provides.