Lecture Seven - Populations Flashcards
When a population overshoots the carrying capacity of the environment, what do you except happens to birth and death rates to reduce the population size to a number closer to the carrying capacity capacity?
A) they will be equal to each other
B) birth rates will be higher than death rates
C) death rates will be higher than birth rates
C) death rates will be higher than birth rates
Why do you think the otter population growth rate started to decrease after 1995?
A) the sea otters got tired of reproducing
B) there are no longer enough resources to support the growing population
C) there were no longer enough sea otters to support a quickly growing population
B) there are no longer enough resources to support the growing population
Which of the following is a good definition of population ecology?
A) the study of change in populations over time
B) the study of mechanisms of speciation
C) the study of how to define a population
D) the study of dispersion patterns
A) the study of change in populations over time
Which of the following processes increase population density (by resulting in individuals entering a populations)? Select all that apply:
A) birth
B) immigration
C) death
D) emigration
A) & B)
Which of the following conditions are required for exponential growth to occur? Select all that apply:
A) unlimited resources
B) density-dependent limiting factors
C) a vacant environment
D) carrying capacity
A) & C)
The main difference between exponential and logistic growth models is:
A) in exponential growth, the population starts out small and increases slowly, while in logistic growth, the population starts out small and increases rapidly
B) exponential growth models produce an S-shaped curve, while logistic growth models produce a J-shaped curve
C) when growth is exponential, there is no carrying capacity, while in logistics growth models, there is a carrying capacity
D) in exponential growth models, there are limited resources, but in logistic growth models, resources are always available
C) when growth is exponential, there is no carrying capacity, while in logistics growth models, there is a carrying capacity
What is a carrying capacity?
A) the growth rate of a population if resources are not limited
B) the maximum population size that can survive in a given environment
C) the rate at which populations grow
D) the size of an area
B) the maximum population size that can survive in a given environment
When is exponential growth realistic?
- When resources are unlimited
- If populations are establishing in a new area
- If populations are recovering from a small size
Are human populations exponential or logistic? Why?
Exponential. Humans are good at reproducing and stretching the carrying capacity with innovations and medicine for death
While studying a population of fungi that you are growing in the lab, you realize that the population growth rate is increasing over time. Given this information, what can you conclude about the type of growth this population is experiencing?
This is exponential growth. This is the case because the fungi are growing rapidly in a new environment from a small population size.
Which of the statements below about exponential population growth is true?
A) When populations grow exponentially, the carrying capacity determines the size at which they will stop growing
B) When populations grow exponentially, the rate of change in population size increases
C) When populations grow exponentially, the rate of change in population size stays the same
D) When populations grow exponentially, the rate of change in population size increases until carrying capacity is reached, and then it starts to decrease
B)
Explain the difference between density-dependent and density-independent limiting factors.
Density-dependent are factors that purposefully control the size of an environment, such as competition, predation and disease. Density-independent are factors that control the size of an environment no matter the size of the environment, such as weather-related events
Which of the following are density-dependent limiting factors for population growth? Select all that apply:
A) predation
B) territoriality
C) drought
D) frost
E) competition
F) disease
G) hurricane
A), B), E), & F)
Consider the graph for birth and death rates per population size (two horizontal lines). Do you think this population is growing? Explain your answer give the information that you have.
No, I do not think this population is growing. Although birth rates are not falling, and they may even be rising, death rates are steady with the birth rates. Therefore, this population cannot be growing in size.
Which of the following will influence the size of a population? Select all that apply:
A) births
B) deaths
C) immigration
D) emigration
ALL OF THE ABOVE
