Biology Chapter 4 - Population Biology Flashcards

Questions and Answers

What is a population?

A group of organisms, all of the same species that live in a specific area.

What do scientists do when studying populations?

They put them in environments with abundant resources to discover growth trends of different species.

What is exponential growth?

When the population gets larger, it grows at a faster rate.

What does a J curve represent?

A population that gets larger, grows at a faster rate, exponential. Signup and view all the answers

What is an S curve in population biology?

A curve where the population graph stabilizes. Signup and view all the answers

What are limiting factors?

Food, disease, and predators are examples of these. Signup and view all the answers

What is carrying capacity?

The number of organisms of one species that an environment can support. Signup and view all the answers

What does the letter 'K' represent in population biology?

Carrying capacity Signup and view all the answers

What is population growth?

More births than deaths. Signup and view all the answers

What indicates population decline?

More deaths than births. Signup and view all the answers

What are rapid life-history patterns?

They are patterns found in small organisms like bacteria. Signup and view all the answers

What characterizes slow life-history patterns?

They live in stable environments, reproduce and mature slowly, and maintain population sizes at or near carrying capacity. Signup and view all the answers

What is population density?

The number of individuals in a given area. Signup and view all the answers

What are density-dependent factors?

Factors that have an increasing effect as the population increases, such as disease, competition, and predators. Signup and view all the answers

What are density-independent factors?

Factors that affect all populations regardless of their density, such as temperature, storms, and floods. Signup and view all the answers

If the number of predators is relatively large, then the number of prey will ____.

decrease Signup and view all the answers

If the number of predators is relatively ____ then the number of prey will increase.

small Signup and view all the answers

What term describes that predation relationships are often?

Cyclical Signup and view all the answers

What happens when populations become large?

The number of organisms in that population begin to compete for limited resources. Signup and view all the answers

What do organisms exhibit when populations increase in a support-limited environment?

Stress Signup and view all the answers

What are symptoms of stress in populations?

Aggression, decrease in parental care, fertility, and resistance to disease. Signup and view all the answers

What does demography study?

The study of human population size, density and distribution, movement, and its birth and death rates. Signup and view all the answers

What special ability sets the human population apart from other organisms?

The ability to change the environment. Signup and view all the answers

What is the birth rate?

The number of births per 1000 people in a given year. Signup and view all the answers

What is the death rate?

The number of deaths per 1000 people in a given year. Signup and view all the answers

What is immigration?

The movement of individuals into a population. Signup and view all the answers

What is emigration?

The movement of individuals out of a population. Signup and view all the answers

The population growth rate must be _____ for the population to decline.

negative Signup and view all the answers

What is doubling time?

The time it takes for a population to double in size. Signup and view all the answers

What does age structure refer to?

The proportions of a population at different age levels. Signup and view all the answers

Why are ecologists concerned by population overload?

Because it affects the food supply. Signup and view all the answers

What do we study demography/ecology to decrease?

Disruptions in wildlife. Signup and view all the answers

Study Notes

Population Biology Key Concepts

A population consists of organisms of the same species living in a specific area.
Studying populations involves creating resource-rich environments that reveal growth trends across different species.
Exponential growth occurs when a population increases rapidly, leading to a significant acceleration in growth rate.
Populations exhibit a J curve during exponential growth phases, illustrating the rapid increase in numbers.
The S curve represents a stabilized population graph when growth reaches equilibrium, indicating resources are limited.

Factors Influencing Population Dynamics

Limiting factors such as food, diseases, and predators restrict population growth.
Carrying capacity defines the maximum number of organisms an environment can sustain.
Population growth arises from the condition of having more births than deaths, while decline results from more deaths than births.

Life History Patterns

Rapid life-history patterns are seen in species like bacteria, which reproduce quickly.
Slow life-history patterns involve organisms that take longer to mature and reproduce, maintaining steady populations near carrying capacity.

Population Density and Its Effects

Population density quantifies the number of individuals within a specific area.
Density-dependent factors (e.g., competition, disease) escalate in impact as population size increases.
Density-independent factors (e.g., weather events) affect all populations regardless of size.

Population Interaction and Stress

High predator numbers can lead to a decrease in prey populations.
Conversely, fewer predators allow prey populations to increase.
Interactions within populations often display cyclical patterns, especially in predation scenarios.
Populations facing an inability to cope with high numbers in limited environments may experience stress characterized by aggression, reduced parental care, and lower fertility rates.

Demographics and Human Population

Demography focuses on human population metrics such as size, density, movement, and rates of birth and death.
The birth rate measures annual births per 1000 individuals, while the death rate captures output of deaths.
Immigration refers to individuals moving into a population, while emigration is the departure of individuals.
A negative population growth rate leads to population decline.
Doubling time refers to the duration required for a population to double its size.
Age structure indicates the distribution of a population across various age levels.

Environmental Concerns

Ecologists are particularly concerned about food supply issues arising from population overload globally.
Disruptions in wildlife and ecosystems motivate the study of demography and ecology for better management and conservation practices.

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Test your knowledge with these flashcards focused on Population Biology from Biology Chapter 4. Each card provides key terms and definitions related to population dynamics and growth trends. Perfect for quick revision and enhancing your understanding of the topic.