Biology Chapter 4 review
Based on the data in the graph, which of the colonies was least affected by temperature as a limiting factor?
3
What are density-independent factors? Give an example.
Density-independent factors can affect populations, regardless of their density. Most density-independent factors are abiotic factors, such as volcanic eruptions, temperature, storms, floods, drought, chemical pesticides, and major habitat disruption. This can take out many populations at one time.
What does an S curve for a population growth indicate?
Eventually, limiting factors, such as availability of food, disease, predators, or lack of space, will cause population growth to slow. Under these pressures, the population may stabilize in an S-shaped growth curve
A country that has a stable population is characterized by an age structure that is _____.
about the same among all groups
An environment's __________ is the number of organisms of a certain species that can be supported indefinitely.
carrying capacity
What does the dotted line represent on this graph?
carrying capacity
For a particular species, the carrying capacity is the maximum number of individual organisms that _____.
could be supported by a given environment indefinitely
Which of these is the study of human population size and the factors that influence it?
demography
Organisms that employ a strategy of slow reproduction usually require an environment that _____.
is stable
Which of these is NOT a characteristic of a rapid life-history organism?
long life span
An elephant is considered to have a slow life-history pattern. Which of these characteristics would be matched to an elephant?
long lifespan
Which of these is NOT a limiting factor to the growth of a population?
long-term abundance of space
What type of population might show an S curve? Is it linear or exponential growth?
A tree population, linear.
What does age structure refer to?
Age structure refers too the number of people in a population that are pre-reproductive and pre-post.
What is fertility rate?
Average number of children a woman will have during her childbearing years which occur between the ages of 15 and 44
Which of these equations represents zero population growth?
Birthrate - Death rate = 0
__________ is a density-dependent factor.
Competition
Which of the following problems do immigration and emigration pose for demographers?
Demographers find it difficult to make predictions about populations.
What are density-dependent factors? Give an example.
Density-dependent factors include disease, competition, predators, parasites, and food. These factors have an increasing effect as the population increases. They depend on populations of organisms. This takes a while to hit every population.
Based on the data in the graph, which of these statements is true? (j shaped)
Growth of the housefly population begins to increase rapidly about 3/4 of the way through the first year.
This graph shows population growth of houseflies. Based on the data in the graph, which of these statements is true? (j shaped)
Growth of the housefly population begins to increase rapidly about 3/4 of the way through the first year.
What type of population might show a J curve? Is it linear or exponential growth?
Human Population, exponential growth.
What is meant by zero population growth?
If the birthrate of a population equals its death rate, then the population growth rate is zero. If the rate is zero, that doesn't mean that the population isn't changing. Rather, it means that new individuals enter the population (by birth and immigration) at the same rate that individuals are leaving (by death and emigration) the population.
How is the age structure different for industrialized countries and developing countries?
In developed nations, more equal distribution. Fertility rate has been constant and survivorship high for a long time. In developing countries, there are many more children than young people because fertility and survivorship are increasing.
The population of a country is experiencing a slow doubling time. Which of these is true of that country?
It can also be categorized as a developed country.
What characteristics does an animal with a slow life-history pattern have?
Large species that live in more stable environments usually have slow life-history patterns. Slow life-history organisms reproduce and mature slowly, and are long-lived. They maintain population sizes at or near carrying capacity.
Which of these is an explanation of why a population can fluctuate once it has reached carrying capacity?
Limiting factors can influence the number of organisms in a population once it reaches carrying capacity.
What characteristics does an animal with a rapid life-history pattern have?
Rapid life-history organisms have a small body size, mature rapidly, reproduce early, and have a short life span.
A population that grows until it reaches its carrying capacity usually has the shape of an ____
S
What does a J curve for population growth indicate?
That the population is growing rapidly.
What is carrying capacity?
The number of organisms of one species that an environment can support indefinitely
A population of rabbits experiences an increase over time. Which of these statements about that population is true?
The population may face increased competition due to resource depletion.
What is demography?
The study of statistics such as births, deaths, income, or the incidence of disease, which illustrate the changing structure of human population.
When is it possible for a population growth rate to be less than zero?
When the death rate is greater than the birthrate.
H
i
The effect of movement of people between counties has _____ effect on total world population.
no
Density-independent factors are limiting factors whose effects are _____.
not influenced by population densities
Bacteria employ a(n) _____ reproductive strategy, a characteristic determined by their small size, rapid maturation, and short life span.
rapid
The giant land tortoises of the Galapagos Islands and sequoias of California have among the longest life spans of any organisms. This indicates that they likely employ a strategy of _____.
slow growth
The population distribution for a country shows that each age structure is about the same size. What type of population growth is this country experiencing?
stable growth
The effect of local population fluctuations in rapidly expanding suburbs may _____ schools, roads, and police and fire services.
stress
