Ecology

Question 1

How can we read phylogenetic trees to make inferences about evolutionary relationships and derived traits?

Answer 1

Understand the different parts of a phylogenetic tree, connect different relationships, and determine evolutionary direction.

Question 2

How do plants acquire what they need to gain biomass?

Answer 2

Through photosynthesis and absorbing nutrients from soil

Question 3

What happens to red blood cells in hypertonic, isotonic, and hypotonic solutions?

Answer 3

Hypertonic: The cell shrinks
Isotonic: The cell remains the same.
Hypotonic: The cell swells and bursts

Question 4

How do humans regulate blood glucose levels?

Answer 4

High blood glucose levels: The pancreas releases insulin, and the liver stores excess glucose as glycogen and reduces levels to normal.
Low Blood Glucose Levels: The pancreas releases glycogen, and the liver breaks down glycogen into glucose, bringing levels back to normal.

Question 5

What are the similarities and differences between open and closed circulatory systems?

Answer 5

Similar: Both transport essential substances, use a heart or pumping mechanism, have circulating fluid, and require energy.
Difference: Closed-use arteries, veins, and capillaries have high pressure, are more efficient, and blood is separate from fluid.

Question 6

What are the evolutionary advantages of having a four-chambered heart?

Answer 6

There is complete separation of oxygen-rich and oxygen-poor blood, which has higher metabolic rates and more beneficial and larger body sizes.

Question 7

What happens at the cellular level within an axon during each stage of an action potential?

Answer 7

Resting rate: -70 mV; all ion channels are closed.
Depolarization: a stimulus raises the potential to -55mV, Na+ gates open, which makes it positively charged.
Repolarization: Na+ channels close, K+ channels open, becoming more negatively charged

Question 8

What is ecology?

Answer 8

Ecology is the scientific study of the interactions of living organisms with their environment.

Question 9

What are the levels of ecological organization?

Answer 9

Organism, Population, Community, Ecosystem, Biosphere

Question 10

What kind of research questions do ecologists ask?

Answer 10

Ex: How does the presence of pollinators impact nutrient cycling?

Question 11

What is a species?

Answer 11

A species is a group of organisms that can interbreed and produce fertile offspring.

Question 12

What is a population, and what are examples of populations?

Answer 12

A population is a group of individuals of the same species that live in the same geographic region and can interbreed and produce fertile offspring.
Ex: All the people living in San Diego

Question 13

What is biogeography?

Answer 13

Biogeography is the study of the geographic distribution of living things and the abiotic factors that affect their distribution.

Question 14

What are the differences between endemic and generalist species?

Answer 14

Endemic: Found only in specific and limited areas
Generalist: Thrive across a range of habitats and areas

Question 15

Why do isolated regions have more endemic species?

Answer 15

There are more physical barriers (oceans), unique climates, less competition, and and less vulnerability to extinction.

Question 16

What abiotic factors constrain populations?

Answer 16

Sunlight, temperature, nutrient availability, water availability, and oxygen availability.

Question 17

What causes seasons?

Answer 17

The rotation of the earth revolved around the sun

Question 18

How does climate change with the seasons

Answer 18

Winter: fewer daylight hours, less sunlight, less heat
Summer: more daylight hours, less sunlight, less heat

Question 19

What is population ecology?

Answer 19

The scientific study of processes that affect the distribution and abundances of species populations.

Question 20

What determines how populations are dispersed in space?

Answer 20

Uniform Distribution: can result from interactions between individuals
Random: can result from wind-dispersed seeds that get randomly distributed
Clumped: can result from animals that travel in groups or resources being unevenly distributed.

Question 21

How do individuals ‘enter’ and ‘exit’ a population?

Answer 21

Individuals enter by birth and immigration and exit by death or emigration.

Question 22

Why do ecologists study birth, death, immigration, and emigration rates in populations?

Answer 22

Type 1 survivorship: have low death rates early and mid-life, but death rates increase in older ages (humans).
Type 2 survivorship: have a constant death rate over the organism’s life span (birds).
Type 3 survivorship: High death rates are at a young age, but death rates decline in older ages (fish).

Question 23

What is exponential growth?

Answer 23

When population growth rate increases over time proportional to the size of the population.

Question 24

What are the assumptions for the exponential population growth model?

Answer 24

• Population closes and only increases/decreases based on birth and death
• Unlimited resources and birth and death rates remain constant.

Question 25

What is the logistic population growth?

Answer 25

As the population size approaches carrying capacity, fewer individuals can be added to the population because of limiting resources.

Question 26

What are the assumptions for the logistic growth models?

Answer 26

- Populations change over time (t) - Resources are often limited in nature. Population size (N) is determined by resource availability. - Carrying capacity (K) is the max population size that an environment can support given limited resources.

Question 27

How can we graph the exponential and logistic growth models?

Answer 27

exponential: J curve logistic: S curve

Question 28

What happens to the birth and death rates as population size approaches carrying capacity?

Answer 28

Birth rates decrease, and death rates increase.

Question 29

how does parental care influence species populations?

Answer 29

r-selected species: small size, fast growth, many offspring, limited parental care, short life span, live in unstable environments K-selected species: large size, slow growth, few offspring, lots of parental care, long life span, live in stable environments.

Question 30

How do reproduction strategy and parental care influence the likelihood of offspring?

Answer 30

- Species that produce many offspring and have lower parental care have lower chances of survival. - Species that produce few offspring and have high parental care have a higher chance of survival.

Question 31

Why are there tradeoffs between offspring number and biological parent survival?

Answer 31

tradeoffs between the number of offspring produced and the amount of resources biological parents can put towards survival

Question 32

what is a community?

Answer 32

A community is a group of two or more populations of different species living in the same geographic area

Question 33

what is community ecology?

Answer 33

the scientific study of interactions between species and their environment

Question 34

What is the difference between species richness and species evenness?

Answer 34

Richness: number of species in a community evenness: proportion each species represents out of all individuals in a community

Question 35

What is species diversity, and how can we identify which communities have higher species diversity?

Answer 35

By determining the species richness and species evenness

Question 36

How do foundation species and ecosystem engineers influence ecological communities?

Answer 36

foundation: create habitat structure for other organisms and are typically highly abundant (trees) Ecosystem engineers create and modify habitat structure by changing the abiotic and biotic environment (beavers)

Question 37

How do keystone species influence species diversity in ecological communities?

Answer 37

Keystone species have a relatively low abundance but have a dramatic impact on their environment. They are the "glue" that keeps the community intact.

Question 38

How do mutualisms, predation, herbivory, parasitism, and competition influence the survival, reproduction, and population dynamics of the species involved?

Answer 38

Mutualism: when both species benefit from the interaction Predation/herbivory: when one species benefits from the interactions and the other is harmed parasites: keep their host alive and benefit from the interaction while the host is harmed Competition: when individuals of different species compete for a limiting resource that limits their survival and reproduction, both are harmed.

Question 39

How does competition impact the distribution of species?

Answer 39

realized niche: the habitat in which a species is found in the presence of competing species fundamental niche: the theoretical habitat a species can be found in nature Ecological release: the expansion of a species niche under conditions where the other species is absent

Question 40

What are disturbance events?

Answer 40

negative impact on an ecological community by killing organisms or altering the availability of resources

Question 41

What are the differences between primary and secondary succession?

Answer 41

primary: new substrate formed, no pre-existing soil (lava) Secondary: previously established, pre-existing soil (wildfire)

Question 42

What is the intermediate disturbance hypothesis?

Answer 42

States that species diversity will be highest at moderate levels of disturbance

Question 43

what is an ecosystem?

Answer 43

a community of living organisms and their interactions with their abiotic environment.

Question 44

what is ecosystem ecology?

Answer 44

the scientific study of the interactions between biotic and abiotic components living in a geographic area

Question 45

Where does energy in an ecosystem come from?

Answer 45

from primary production, which is the production of new organism material by autotrophs

Question 46

Why is the world green?

Answer 46

because the world is covered in plants

Question 47

How do top-down vs. bottom-up processes influence populations?

Answer 47

Top-down: consists of the influences of consumers on communities Bottom-up: consists of the influences abiotic factors have on communities.

Question 48

How are feeding relationships depicted in ecological communities?

Answer 48

Food webs, which are summaries of feeding interactions in a community

Question 49

what are the different trophic levels of a food web?

Answer 49

primary producer, primary consumer, secondary consumer, tertiary consumer

Question 50

how do autotrophs increase biomass?

Answer 50

photosynthesis

Question 51

What is the difference between gross primary production and net primary production?

Answer 51

gross: the total primary production by all primary producers net: the amount of chemical energy available to consumers, including metabolism

Question 52

What is secondary production, and how does it create new biomass?

Answer 52

the production of biomass

Question 53

how much chemical energy is available to consumers by the ecosystem?

Answer 53

10% of what was transferred from the thing they consumed

Question 54

Why is the transfer of chemical energy through a food web inefficient?

Answer 54

because it's too broad

Question 55

How can we depict the transfer of chemical energy?

Answer 55

The arrows point to the direction of energy flow.