Chapter 6: Population Ecology (Alex)

Question 1

What is a group of organisms of the same species that inhabits a defined geographic area at the same time?

Answer 1

A population

Question 2

What term refers to the number of individuals of a population that inhabit a certain unit of land or water area.

Answer 2

Population density

Question 3

What term refers to how individuals are spaced within a region.

Answer 3

Population dispersion

Question 4

What type of population spacing does random describe?

Answer 4

The position of each individual is not determined or influenced by the other members of the population.

Question 5

What type of population spacing does clumping describe?

Answer 5

Clumping is the most common dispersion pattern for populations. In this type of dispersion, individuals “flock together.”

Question 6

What type of population spacing does uniform describe?

Answer 6

The members of the population are uniformly spaced throughout their geographic region.

Question 7

What is the biotic potential of a population?

Answer 7

The amount that the population would grow if there were unlimited resources in its environment. Not very practical

Question 8

What is the carrying capacity (K) of a particular region?

Answer 8

The maximum population size that can sustainable be supported by the available resources in the region.

Question 9

What is logistic population growth?

Answer 9

Logistic population growth is a much better model for what exists in natural settings and it basically says that when populations are well below the size dictated by the carrying capacity of the region they live in, they will grow exponentially, but as they approach the carrying capacity, their growth rate will decrease and the size of the population will eventually become stable.

Question 10

What is the Rule of 70?

Answer 10

A rule that lets you approximate the time it will take for a population to double by dividing 70 by the current growth rate of the population.

Question 11

What is an r-selected organism?

Answer 11

An r-selected organism is one that reproduces early in life and often has a high capacity for reproductive growth. Some examples are bacteria, algae, and protozoa. Little or no care is given to offspring and many are created.

Question 12

What is a k-selected organism?

Answer 12

A k-selected organism reproduces later in life, produces less offspring, and devotes significant time and energy to the nurturing of their offspring. Some examples are humans, lions, and cows.

Question 13

What is the boom-and-bust cycle?

Answer 13

The boom-and-bust cycle is very common among r-strategists. In this type of cycle, there is a rapid increase in population and then an equally rapid drop off.

Question 14

What are some density-dependent factors in population growth?

Answer 14

Increased predation, competition for food or living space, disease, and the buildup of toxic materials.

Question 15

What are some density-independent factors in population growth?

Answer 15

Fires, storms, earthquakes, and other catastrophic events

Question 16

What organism does a Type I (K-selected) survivorship curve represent?

Answer 16

One where the majority of it’s offspring will live for a long period of time; eventually they will start to die off

Question 17

What organism does a Type II survivorship curve represent?

Answer 17

One where its offspring have a fifty-fifty chance of surviving to old age.

Question 18

What organism does a Type III (r-selected) survivorship curve represent?

Answer 18

One where most of its offspring will die young, but if they live to a certain age, they will live a longer life

Question 19

According to the U.S. Census Bureau as of January 2017, what is the estimated world population?

Answer 19

7,366,958,890

Question 20

What is the crude birth rate?

Answer 20

The number of live births per 1,000 people in a year

Question 21

What is the crude death rate?

Answer 21

The number of deaths per 1,000 people in a year

Question 22

What is the movement of people out of a population called?

Answer 22

Emmigration

Question 23

What is the movement of people into a population called?

Answer 23

Immigration

Question 24

What is the total fertility rate (TFR)?

Answer 24

The number of children a woman will bear in her lifetime on average.

Question 25

What is the replacement birth rate?

Answer 25

The number of children a couple must have to replace themselves in a population.

Question 26

What are age-structure pyramids (age-structure diagrams) used for and what subcategories are they split into??

Answer 26

They are used to graphically represent human populations and they are split into pre-reproductive (0-14), reproductive (15-44), and post-reproductive (45+).

Question 27

What is the demographic transition model used for?

Answer 27

It is used to predict population trends based on the birth and death rates of a population.

Question 28

When a population moves from the ____ stage to the ____ stage it is called demographic transition.

Answer 28

First, second

Question 29

Describe the preindustrial state (stage 1)

Answer 29

In this state, the population exhibits a slow rate of growth and has a high birth rate and high death rate because of harsh living conditions. Harsh living conditions can be considered environmental resistance, an umbrella term for conditions that slow a population’s growth.

Question 30

Describe the transitional state (stage 2)

Answer 30

In this second state, birth rates are high, but due to better food, water, and health care, death rates are lower. This allows for rapid population growth. Birth rates remain high due to cultural or religious traditions and a lack of education for woman.

Question 31

Describe the industrial state (stage 3)

Answer 31

In the third state, population growth is still fairly high, but the birth rate drops, becoming similar to the death rate. Many developing countries are in the currently in the industrial state.

Question 32

Describe the postindustrial state (stage 4)

Answer 32

In the final stage, the population approaches and reaches a zero growth rate. Populations may also drop below the zero growth rate and some consider this a 5th stage.

Question 33

What are four of the most significant factors that have contributed to the increase in human population?

Answer 33

Improved nutrition, the availability of clean water, newly implemented systems for sanitary waste disposal, and better medical care. Another significant factor is the increase in food production.

Question 34

What type of nutrients are needed in large amounts and include proteins, carbohydrates, and fats?

Answer 34

Macronutrients

Question 35

What type of nutrients are needed in smaller amounts and include vitamins, iron, and minerals?

Answer 35

Micronutrients

Question 36

What is hunger?

Answer 36

Hunger is when insufficient calories are taken in to replace those being expended.

Question 37

What is malnutrition?

Answer 37

Poor nutrition that results from an insufficient or poorly balanced diet.

Question 38

What is undernourishment?

Answer 38

When one has not been provided with sufficient quantity or quality of nourishment to sustain proper health and growth/

Question 39

What is a food desert?

Answer 39

A place where access to fresh, healthy food is difficult. The residents rely on low quality processed foods for subsistence.