Population Dynamics Assignment
Name: ________________________
14.1 Characteristics of Populations
Definitions to write out: population, dispersion (clumped, random, uniform), quatrat sampling, mark recapture, population
size and density
Questions (write out complete responses)
1. The number of yeast in a large vat can be determined by a quadrat sampling method. The quadrat, in this case is a pipet
which samples 1.0 mL (0.0010L). The yeast are then counted using a microscope. Five samples are taken from the vat, and
yeast count estimates of 982, 837, 1023, 915, and 1064 are recorded. Estimate the number of yeast in the 29 L vat.
2. In a river in Ontario, 270 Atlantic salmon were captured and fin-marked with a numbered T-bar anchor tag. Two weeks
later, a total of 112 Atlantic salmon were recaptured, and 11 carried the T-bar anchor tags. Estimate the Atlantic salmon
population in this river during this study.
3. A small garden pond contains 38 goldfish at the beginning of the summer. There is no reproduction, but during the summer
15 are eaten by raccoons and the garden-owner adds 20 from the pond supply store. Full solutions are required.
Determine the population size at the end of the summer.
Determine the growth rate of the population over the summer.
1. Answer: 2.8 x 10 7 yeastAnswer: The river held 2749 Atlantic salmon during the 2-week study3. Answer: the population size
at the end of the summer is 43 fish and the population has a growth rate of 13%.
14.2 Measuring and Modeling Population Change
Definitions to write out: carrying capacity, biotic potential, limiting factor, fecundity, fertility, reproductive potential,
population change, closed vs. open population, survivorship patterns (I, II, III), geometric growth vs. exponential growth,
instantaneous growth rate, doubling time, logistic growth rate, logistic growth curve
Questions (write out complete responses)
1. Each May, harp seals give birth on pack ice off the coast of Newfoundland and Labrador. In a hypothetical situation, an
initial population of 1500 seals gives birth to 680 pups, and during the next 12 months, 90 seals die. Assuming that the
population is growing geometrically, what will the harp seal population be in 11 years?
2. Each May, harp seals give birth off the coast of Newfoundland and Labrador. In a hypothetical situation, an initial
population of 900 seals gives birth to 390 pups, and during the next 12 months, 60 seals die.
3. Assuming that the population is growing geometrically, what will the harp seal population be in 12 years?
A population of squirrels in a local park exhibits geometric growth. The initial population size is 43 squirrels. During the year
being studied, 77 young are born, and 21 squirrels are lost to predators and accidents.
A) Calculate the geometric growth rate. A formal solution is required.
B) Is it reasonable to assume that the population will continue to increase at this rate? Explain why you made this conclusion.
4. During the summer, a population of aphids exhibits exponential growth on rose bushes. The initial population of aphids on
a rose bush is 53 and their intrinsic rate of increase is 0.281 per day. Calculate the initial instantaneous growth rate.
5. A population of 1750 yeast cells in a culture tube is growing exponentially. If the intrinsic growth rate (r) is 0.023 per
hour, calculate the initial instantaneous growth rate, dN/dt.
6. A hypothetical population has a per capita growth rate of 3.5% per year. Determine the approximate time needed for the
population to double in size.
7. Historical records suggest that in A.D. 1650, the human population was growing such that the population doubled in 200
years. Determine the intrinsic growth rate of the human population in 1650 as a percent.
8. The Irish Potato famine occurred in 1850, however, historical records suggest that in A.D. 1850, the human population
was growing such that the population doubling time was 100 years. Determine the intrinsic growth rate as a percent.
9. In a population of lobsters where growth is continuous, the carrying capacity of the environment is 1000 individuals. The
initial population has a maximum intrinsic growth rate of 0.235 per year.Calculate the rate of logistic growth of the population
over three years, by completing the table. Provide a formal solution of the population increase for 1 year.
The population size is 170.
10. A population is growing continuously. The carrying capacity of the environment is 800 individuals and the maximum
growth rate is 0.35. a) Determine the population growth rate if the population size is 20 individuals. A formal solution is
required.
b) How would this rate compare to the rate if the population was very near the carrying capacity? A calculation is not required.
11. A population is growing continuously. The carrying capacity of the environment is 780 individuals and the maximum
growth rate is 0.35. a) Determine the population growth rate if the population consists of 700 individuals. The carrying
capacity is 800.
b) How does this rate compare to the rate that would be calculated with a much smaller population? A calculation is not
required.
Answers
1.With the same growth rate, the seal population will have reached 60 743 at the end 11 years2.With the same growth rate, the
seal population will reach 39 330 after 12 years.3. a)The geometric growth rate of the squirrel population is 2.3
b)It is not reasonable to assume a constant growth rate. The park has a carrying capacity determined by food, shelter and
space requirements of the population. Once this is reached, the growth rate will decline.
4. The aphid population has an initial instantaneous growth rate of 15 aphids/h.
5. The initial instantaneous growth rate is 40/h. 6. The population should double in approximately 20 years. 7. The growth rate
of the human population in 1650 was 0.34%.
8. The growth rate of the human population in 1850 was 0.69%.
9. The logistic growth rate is 33 per year.
10. a) The population growth rate is 6.8 when the population has 20 individuals.
b) Nearing the carrying capacity, the rate would be declining/approaching zero.
11. a) The population growth rate is 6.8 when the population numbers 700 individuals. b) The growth rate would be much
lower.
14.3 Factors Affecting Population Change & 14.4 Interactions Within Communities
Definitions to write out: density dependent vs independent factors, interspecific vs intraspecific competition, predation,
minimum viable population size, the allele effect, obligatory mutualism, mutualism, commensalisms, limiting factor,
ecological niche, ectoparasite, mimicry, visual warning, habitat, fundamental vs. realized niche, parasitism, passive defense
mechanisms vs active defense, exotic species
SBI4U
DATE: _____________________________
NAME: ____________________________
Lesson Problems to follow Powerpoint Lesson
•
•
Do you have your calculator with you?
You will need it.
14.1 Characteristics of Populations
Population Size and Density
A backyard measuring 3.0 m by 4.0 m contains 215 dandelions. Determine the population density of the plants.
A small field having an area of 1.5 ha contains a pond with a surface area of 0.3 ha and is home to 300 field mice. Determine
the ecological density of the mouse population.
Estimating Population Size and Density
A lawn-care company wishes to estimate the density of a weed population in a park before spraying. The park measures 100 m
x 50 m. The technician randomly places four 1.0 m x 0.5 m quadrats in the park, and finds weed counts of 11, 23, 16 and 20
plants in the 4 quadrants. Estimate the density of the population.
Mark-Recapture Sampling
A grade 10 Science class of 28 students has been tagged by their teacher. Later in the day, 3 tagged students were observed in
an English class of 30. Estimate the number of grade 10 students in the school.
A small garden pond having a volume of 1.7 m is to be stocked with ornamental goldfish. If the recommended population
density for the fish is 37 fish/m, how many goldfish should be put in the pond?
A population of moose, numbering 27 individuals, is being relocated to allow developers to build a golf course in Northern
Ontario. If the moose can prosper at a density of 0.8 moose/ha, what is the smallest area into which the moose can be moved?
14.1 Characteristics of Populations
Definitions to write out: population, dispersion (clumped, random, uniform), quatrat sampling, mark recapture, population
size and density
Questions (write out complete responses)
1. The number of yeast in a large vat can be determined by a quadrat sampling method. The quadrat, in this case is a pipet
which samples 1.0 mL (0.0010L). The yeast are then counted using a microscope. Five samples are taken from the vat, and
yeast count estimates of 982, 837, 1023, 915, and 1064 are recorded. Estimate the number of yeast in the 29 L vat.
2. In a river in Ontario, 270 Atlantic salmon were captured and fin-marked with a numbered T-bar anchor tag. Two weeks
later, a total of 112 Atlantic salmon were recaptured, and 11 carried the T-bar anchor tags. Estimate the Atlantic salmon
population in this river during this study.
3. A small garden pond contains 38 goldfish at the beginning of the summer. There is no reproduction, but during the summer
15 are eaten by raccoons and the garden-owner adds 20 from the pond supply store. Full solutions are required.
Determine the population size at the end of the summer.
Determine the growth rate of the population over the summer.
1. Answer: 2.8 x 10 7 yeastAnswer: The river held 2749 Atlantic salmon during the 2-week study3. Answer: the population size
at the end of the summer is 43 fish and the population has a growth rate of 13%.
14.2 Measuring and Modeling Population Change
Definitions to write out: carrying capacity, biotic potential, limiting factor, fecundity, fertility, reproductive potential,
population change, closed vs. open population, survivorship patterns (I, II, III), geometric growth vs. exponential growth,
instantaneous growth rate, doubling time, logistic growth rate, logistic growth curve
Questions (write out complete responses)
12. Each May, harp seals give birth on pack ice off the coast of Newfoundland and Labrador. In a hypothetical situation, an
initial population of 1500 seals gives birth to 680 pups, and during the next 12 months, 90 seals die. Assuming that the
population is growing geometrically, what will the harp seal population be in 11 years?
13. Each May, harp seals give birth off the coast of Newfoundland and Labrador. In a hypothetical situation, an initial
population of 900 seals gives birth to 390 pups, and during the next 12 months, 60 seals die.
14. Assuming that the population is growing geometrically, what will the harp seal population be in 12 years?
A population of squirrels in a local park exhibits geometric growth. The initial population size is 43 squirrels. During the year
being studied, 77 young are born, and 21 squirrels are lost to predators and accidents.
A) Calculate the geometric growth rate. A formal solution is required.
B) Is it reasonable to assume that the population will continue to increase at this rate? Explain why you made this conclusion.
15. During the summer, a population of aphids exhibits exponential growth on rose bushes. The initial population of aphids on
a rose bush is 53 and their intrinsic rate of increase is 0.281 per day. Calculate the initial instantaneous growth rate.
16. A population of 1750 yeast cells in a culture tube is growing exponentially. If the intrinsic growth rate (r) is 0.023 per
hour, calculate the initial instantaneous growth rate, dN/dt.
17. A hypothetical population has a per capita growth rate of 3.5% per year. Determine the approximate time needed for the
population to double in size.
18. Historical records suggest that in A.D. 1650, the human population was growing such that the population doubled in 200
years. Determine the intrinsic growth rate of the human population in 1650 as a percent.
19. The Irish Potato famine occurred in 1850, however, historical records suggest that in A.D. 1850, the human population
was growing such that the population doubling time was 100 years. Determine the intrinsic growth rate as a percent.
20. In a population of lobsters where growth is continuous, the carrying capacity of the environment is 1000 individuals. The
initial population has a maximum intrinsic growth rate of 0.235 per year.Calculate the rate of logistic growth of the population
over three years, by completing the table. Provide a formal solution of the population increase for 1 year.
The population size is 170.
21. A population is growing continuously. The carrying capacity of the environment is 800 individuals and the maximum
growth rate is 0.35. a) Determine the population growth rate if the population size is 20 individuals. A formal solution is
required.
b) How would this rate compare to the rate if the population was very near the carrying capacity? A calculation is not required.
24. A population is growing continuously. The carrying capacity of the environment is 780 individuals and the maximum
growth rate is 0.35. a) Determine the population growth rate if the population consists of 700 individuals. The carrying
capacity is 800.
b) How does this rate compare to the rate that would be calculated with a much smaller population? A calculation is not
required.
Answers
1.With the same growth rate, the seal population will have reached 60 743 at the end 11 years2.With the same growth rate, the
seal population will reach 39 330 after 12 years.3. a)The geometric growth rate of the squirrel population is 2.3
b)It is not reasonable to assume a constant growth rate. The park has a carrying capacity determined by food, shelter and
space requirements of the population. Once this is reached, the growth rate will decline.
4. The aphid population has an initial instantaneous growth rate of 15 aphids/h.
5. The initial instantaneous growth rate is 40/h. 6. The population should double in approximately 20 years. 7. The growth rate
of the human population in 1650 was 0.34%.
8. The growth rate of the human population in 1850 was 0.69%.
9. The logistic growth rate is 33 per year.
10. a) The population growth rate is 6.8 when the population has 20 individuals.
b) Nearing the carrying capacity, the rate would be declining/approaching zero.
11. a) The population growth rate is 6.8 when the population numbers 700 individuals. b) The growth rate would be much
lower.