Exam 6 Material (Intro to Ecology and Populations)

Question 1

What is being described?:
- environmental science (how humans influence the environment), conservation biology (trying to conserve biodiversity), fishing management, forestry, and the science of agriculture

Answer 1

Related fields of ecology

Question 2

At what levels can we study ecology?

Answer 2

• Individual
• Population
• Community
• Ecosystem

Question 3

What do we have to take into account when talking about populations?

Answer 3

• Population size
• Population density
• Population dynamics

Question 4

What is being described?:
- is related to population density and is how are the individuals in the population spread out

Answer 4

Population dispersion

Question 5

What four fundamental things are included in population growth (two increase the population and two decreases the population)?

Answer 5

• Birth
• Immigration
• Death
• Emigration

Question 6

What is being described?:
- is how a population grows (this would be the equivalent of what is called exponential growth, which has a slow beginning but rapid growth after a certain period) (however, this is pretty unusual because often a population’s growth is limited by the resources it needs like food, water, space and there is not enough to go around for everybody so some people are going to get left out) (will eventually reach carrying capacity)

Answer 6

Growth curve

Question 7

What is being described?:
- is the idea of species being “R-selected” or “K-selected”

Answer 7

Life history traits

Question 8

Which type of species is being described?:
- species have evolved to be somewhere around that 0 population growth, their births and deaths are roughly the same/they don’t have a lot of babies (but they take really good care of the babies they do have), and they are slow growing, they have babies late in life, they are pretty big and sturdy, and they don’t die very often (are around carrying capacity)

Answer 8

“K-selected” species

Question 9

What is being described?:
- are things that are going to influence the population’s growth but are NOT dependent upon density (ex: weather, earthquakes, mudslides, meteors hitting the Earth—those things are typically abiotic and are going to happen regardless of the density of the population and they’re going to have an influence on the population regardless of the density of the population) (teams up to density-dependent factors to influence population growth)

Answer 9

Density-independent factors

Question 10

Which type of species is being described?:
- Some species have lots of babies over the course of their life/have babies multiple times (repeated births) (we see this with “K-selected” species)
* The key to this concept is trade-offs

Answer 10

Iteroparous species

Question 11

What is being described?:
- is one that is made up of several smaller populations that are linked together through migration (immigration and emigration) and when those individuals travel between those locations, they breed in those new locations and which increases the gene flow (this allows for a mixing of the genes among these different populations, which helps avoid things like inbreeding)
- Some populations have lower-quality habitats, which means the population doesn’t grow as well (might even have negative growth), but if they’re linked to source populations (have really good resources/habitats) then the excess individuals will move out and move into those other areas and resupply them

Answer 11

Metapopulation

Question 12

What is being described?:
- the scientific study of interactions between organisms and biotic and abiotic factors making up their environment (the key here is interactions)

Answer 12

Ecology

Question 13

Which ecological factor is being described?:
- refers to any living thing (the living things in an organism’s environment)

Answer 13

Biotic factors

Question 14

Which ecological factor is being described?:
- refers to the nonliving environment (physical things like sunlight, water, and air) that organisms are interacting with

Answer 14

Abiotic factors

Question 15

Which level of ecology is being described?:
- how a single organism interacts with its environment

Answer 15

Individual level

Question 16

Which level of ecology is being described?:
- all of the individuals of a given species living in a given area at the same time) (ex: all of the raccoons in Cook County)

Answer 16

Population-level

Question 17

Which level of ecology is being described?:
- looks at all the different populations of different species that live and interact in a given area at the same time) (ex: all of the community on SXU’s campus)

Answer 17

Community-level

Question 18

Which level of ecology is being described?:
- not only the community but all of the biotic AND abiotic factors interacting together within a given area at the same time) (ex: community + abiotic factors)

Answer 18

Ecosystem-level

Question 19

Which aspect of population is being described?:
- is going to be all of the individuals of that certain species in that certain area at that certain time (ex: all of the Eastern Bunnies on SXU campus on Monday of some year)

Answer 19

Population size

Question 20

Which aspect of population is being described?:
- takes into account the number of those individuals not just the total number but the number per unit of area) (ex: per square kilometer)

Answer 20

Population density

Question 21

Which aspect of population is being described?:
- are going to be the hows and whys of a population going up or down (things that are going to influence why that population is going up or down)

Answer 21

Population dynamics

Question 22

Which type of population dispersion is being described?:
- is almost never if ever, occurring

Answer 22

Random dispersion

Question 23

Which type of population dispersion is being described?:
- means that all of the individuals are pretty evenly spread out across the area (an equivalent distance from each other) (you will see this under territoriality or severe compensation for the resources and everyone is pretty evenly spaced out) (seen in nesting birds)

Answer 23

Uniform dispersion

Question 24

Which type of population dispersion is being described?:
- is perhaps the most common and it means that because resources that these animals or plants need are clumped in very specific areas, then those organisms are going to be clumped in those specific areas (wherever the resources are, the life follows) (it is NOT random, it’s where the food is located or where the shelter/water is located)

Answer 24

Clumped dispersion

Question 25

Which fundamental aspects of population growth INCREASE it?

Answer 25

Birth and immigration

Question 26

Which fundamental aspects of population growth DECREASE it?

Answer 26

Death and emigration

Question 27

When is a population stable?

Answer 27

When the four aspects (birth, immigration, death, and emigration) are balanced/add up to the same number

Question 28

What are examples of density-dependent factors?

Answer 28

• Food
• Water
• Shelter

Question 29

What is being described?:
- when the growth of the population is essentially 0, which means your births and deaths/immigration and emigration are all equalling out to roughly 0—is also the number of individuals a population size can support indefinitely

Answer 29

Carrying capacity

Question 30

What is being described?:
- are species that have evolved to make lots of babies (kind of displayed exponential growth) but because resources are limited, their population would normally collapse, but often because they’re all about reproducing as fast as possible, they often tend to have small body sizes, small babies (they can get killed easily), which is a trade-off (ex: mouse vs. elephant)

Answer 30

“R-selected” species

Question 31

What is being described?:
- are those that put all of their reproduction into one attempt and then they die (we see this with “R-selected” species)
* The key to this concept is trade-offs

Answer 31

Semelparous species