Ecology

Question 1

What is an ecosystem?

Answer 1

It is a community of living organisms with nonliving components in an environment interacting as a system

Question 2

What does the term population refer to in ecology?

Answer 2

The number of individuals of one species of organism in an ecosystem.

Question 3

What is the 10% rule that we discussed in class?

Answer 3

As you move up the trophic levels, only 10% of the energy is transferred.

Question 4

What is a niche and why is it important to a species and an ecosystem?

Answer 4

It is where that animal fits into the ecosystem-what it eats, where it lives, what time of day it is awake, etc.

Question 5

Why would an ecosystem need an abundance of producers in order to be stable? What would happen if the producers suddenly decreased?

Answer 5

The producers are the base of the food web, they are where energy is able to enter the food web and if they suddenly decreased there would be a shortage of food for primary consumers, so those would die off, then there would be a shortage of food for the secondary and tertiary consumers.

Question 6

Carrying capacity refers to:

Answer 6

The number of organisms in a population that an ecosystem can maintain over a long period of time.

Question 7

Is there a carrying capacity for all living organisms? Why or why not?

Answer 7

Yes, because we only have one earth to live on. In general, in an ecosystem where all the organisms are where they belong (no invasive species) each species will be limited in its growth by several varying limiting factors.

Question 8

What happens when a population reaches carrying capacity?

Answer 8

It fluctuates around that carrying capacity slightly.

Question 9

What are 3 things would increase the population density of a group?

Answer 9

More births, increased immigration, decreased emigration

Question 10

How do you calculate population density?

Answer 10

Number of organisms/ area

Question 11

If Yellowstone has 2500 elk in 25 square miles, what is the population density?

Answer 11

2500/25=100 elk per square mile

Question 12

If Yellowstone has 175 coyotes in 25 square miles, what is the population density?

Answer 12

175/25=7 coyotes per square mile

Question 13

Predator-prey is a type of relationship that organisms can have with each other. List the other 4 types and give a NEW example of each.

Answer 13

1. Commensalism 2. Mutualism 3. Parasitism 4. Competition

Question 14

What are the 2 different type of population growth? Which one is realistic? Why?

Answer 14

1. Logistic- (logical) the population has a carrying capacity that is determined by the limiting factors of the ecosystem 2. Exponential-population grows indefinitely and without being limited by factors

Question 15

What does a limiting factor do to populations? How does this relate to carrying capacity?

Answer 15

Limits the population’s ability to grow, maintains the population at the carrying capacity instead of letting it grow unchecked

Question 16

List 2 biotic and 2 abiotic limiting factors to the fish in my fish tank.

Answer 16

Biotic: 1. Plant material available to produce food and oxygen 2. Fish/other producers to make CO2 for the plants
Abiotic: 1.Living space 2. water

Question 17

What is an invasive species? Why do scientists work to reduce this happening?

Answer 17

A species that comes into an ecosystem where it doesn’t naturally occur. They can be troublesome and greatly affect the ecosystem’s balance and use up resources that should be used by the organisms that naturally occur in that ecosystem.

Question 18

Do invasive species always take over an ecosystem? Why or why not?

Answer 18

No, sometimes they can’t survive in that new ecosystem

Question 19

Define and describe negative feedback systems. Give an example.

Answer 19

These maintain a system’s equilibrium. Ex: heater in a house, pH of blood

Question 20

Define and describe positive feedback systems. Give an example.

Answer 20

Continues to increase the amount of something, ex. Bank account balance and interest

Question 21

What is the balanced chemical reaction for cellular respiration?

Answer 21

C6H12O6 +6 O2 –> 6 CO2 + 6 H2O + energy

Question 22

What are the products of photosynthesis?

Answer 22

Glucose and oxygen

Question 23

Why do plants do both cellular respiration and photosynthesis?

Answer 23

They perform photosynthesis to make their food, then cellular respiration to digest the food for energy for their cells.

Question 24

Non-renewable resources

Answer 24

Natural resource that cannot be re-made or re-grown at a scale comparable to its consumption

Question 25

Nuclear energy

Answer 25

Non-renewable, its when nuclear fission uses uranium to create energy. Its non-renewable because once the uranium is used, it is gone

Question 26

Fossil Fuels

Answer 26

Coal, petroleum, and gas are considered non-renewable because they cannot be replenished in a short period of time.

Question 27

Renewable resources

Answer 27

Natural resources that can be replenished in a short period of time

Question 28

Solar

Answer 28

Renewable resource, energy from the sun

Question 29

Geothermal

Answer 29

Renewable resource, energy from Earth’s heat. Heats water within the Earth and it spins turbines

Question 30

Wind

Answer 30

Renewable resource, energy from the wind

Question 31

Biomass

Answer 31

Renewable resource, energy from burning organic or living matter. Example would be burning trees

Question 32

Water or hydroelectric

Answer 32

Renewable resource, Energy from the flow of water. Why not renewable? Damage to habitat and pushes states to increase other clean sources