⭐7.1-7.3 Mastery Check

A population is...

• A group of one species in one area

• Multiple species that live in one area

• All of the living and nonliving things in an area

• None of these

Answer explanation

A population refers to a group of one species in one area. It does not include multiple species or nonliving things. The correct choice is 'A group of one species in one area', as it accurately defines a population in ecological terms.

If the number of births in a population is the same as the number of deaths in a population, what will happen to the growth of the population?

• It will increase.

• It will decrease.

• It will stay the same.

• It will fluctuate.

Answer explanation

In a population, if the number of births is equal to the number of deaths, the growth of the population will remain the same. This is because the number of people being added to the population through births is being balanced by the number of people leaving the population through deaths, resulting in no net change in population size.

When organisms move out of the population, this is known as

• emigration

• abandonment

• immigration

• succession

Answer explanation

Emigration refers to the process when organisms move out of a population. In contrast, immigration is when organisms move into a population. Abandonment and succession are not related to the movement of organisms in or out of populations. Therefore, the correct choice is emigration.

Any thing or organism that regulates the size of a population of another organism is known as __________.

• a limiting measure

• a limiting factor

• factorization

• materialization of precipitation

Answer explanation

In the context of the question, the term that describes anything or organism that regulates the size of a population of another organism is 'a limiting factor'. This term is used in ecology to refer to the environmental conditions that limit the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem. The other options do not accurately fit the context of the question.

Tags

NGSS.MS-LS2-4

Which of the following are density dependent factors?

• competition for resources

• predation

• disease

• natural disasters

Answer explanation

Density-dependent factors are those that become more effective as the population density increases. These include competition for resources, predation, and disease. As the population grows, the resources become scarce leading to competition. Similarly, predation and disease spread more easily in denser populations. Natural disasters, on the other hand, are density-independent as they can occur regardless of the population density.

Tags

NGSS.MS-LS2-4

Which of the following are examples of a density independent factors?

• forest fire

• seasonal cycles

• storms

• disease

Answer explanation

Density independent factors are events that affect the population regardless of its size. These are typically abiotic factors such as weather and climate, natural disasters, and certain human activities. Therefore, options like forest fire, seasonal cycles, and storms are examples of density independent factors. Disease, on the other hand, is a density dependent factor as its effect varies with population density.

Tags

NGSS.MS-ESS3-2

Which of the following would INCREASE the carrying capacity of an ecosystem?

• increase in predators

• disease

• increase in available food

• drought

Answer explanation

The carrying capacity of an ecosystem refers to the maximum population size of a species that the environment can sustain indefinitely. This is determined by the availability of resources such as food, water, and space. Therefore, an increase in available food would increase the carrying capacity of an ecosystem, as it would allow for a larger population to be sustained.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

When the birthrate of a population exceeds (more than) its death rate, the population

• decreases

• increases

• stays the same

• increases then decreases

Answer explanation

The question asks what happens to a population when the birthrate exceeds the death rate. The correct answer is that the population increases. This is because when more individuals are being born than are dying, the total number of individuals in the population will naturally go up.

The number of organisms in a population born in a year.

• Birth Rate

• Death Rate

Answer explanation

The question asks about the number of organisms in a population that are born in a year. The correct answer is 'Birth Rate'. This term refers to the number of births in a population over a specific period, typically one year. The 'Death Rate', on the other hand, refers to the number of deaths in a population over a specific period. Therefore, 'Birth Rate' is the correct choice.

What pattern of population distribution does this school of fish represent?

• Random

• Uniform

• Clumped

• Knotted

Answer explanation

The school of fish represents a 'Clumped' pattern of population distribution. This is because fish tend to group together for protection, food availability, and mating purposes. The other options, 'Random', 'Uniform', and 'Knotted', do not accurately describe this behavior.