Environment Bronze Qs Unit 3

Question 1

Describe a decomposer and list two examples

Answer 1

A decomposer is an organism that breaks down organic material

Bacteria and fungi are examples of decomposers

Question 2

Describe the essential role decomposers play in an ecosystem

Answer 2

They help with cycling important nutrients such as nitrogen and carbon through an ecosystem

They move the nutrients from biotic, to abiotic parts of a ecosystem. Then the nutrients become available to producers

Question 3

Explain what would happen if there were no decomposers

Answer 3

Without decomposers, there would be no recycling of nutrients needed by producers for making new organic matter. Meaning the ecosystem would eventually run out of nutrients and stop working

Question 4

Explain why a food chain is useful to ecologists

Answer 4

Food chains describe how energy in the form of food passes from one organism to another in an ecosystem

This is helps ecologist divide organisms that make up a food chain into three categories (producers, consumers, and decomposers)

Question 5

Explain the difference between a primary consumer and a secondary consumer. List two examples of each

Answer 5

Primary consumers
-Eat plants (herbivores)

Examples
Mice
Rabbits

Secondary Consumers
-Eat other organisms (carnivores)

Examples
Foxes
Wolves

Question 6

Describe what happens to some of the energy as it passes through each trophic level of a food chain

Answer 6

As energy passes through each link in the food chain, some if it is lost as heat. Additionally, not all organisms (such as primary consumers) are consumed by carnivores)

Thus each trophic level has less energy

Question 7

Explain why an ecosystem will always have fewer predators compared with the number of primary consumers or producers

Answer 7

The lack of available energy (at higher trophic level) limits the number of consumers (predators) that can exist at those levels within a particular ecosystem.

Therefore, there will always be fewer predators in a ecosystem than primary consumers.

Question 8

Describe the two locations where precipitation can end up other than runoff to rivers, lakes, and oceans

Answer 8

Aquifer

Locked up in glaciers and snow caps

Question 9

Explain how the hydrologic cycle purifies water

Answer 9

During the evaporation phase of the cycle, the water molecules leave, while the other nasty stuff, stays behind. Thus purifying the water

Question 10

In what ways does nitrogen in the biotic part of an ecosystem return to the abiotic part of an ecosystem

Answer 10

Waste and decomposition (living organisms (the biotic part of the environment) produce waste with the nitrogen that goes to the ground (the abiotic part of the environment)

When living organisms die- the nitrogen in their bodies then get’s absorbed by the abiotic part of the environment through decomposition .

Question 11

What are the most important organisms that participate in the nitrogen cycle? Explain why they are important

Answer 11

Bacteria are the most important because they make up the majority of living organisms who can break down nitrogen in the air and ground

Question 12

Describe what type of organisms form the base of energy flow pyramids

Answer 12

Producers, plants, such as trees and bushes

Question 13

A typical ecosystem has about 10% ecological efficiency. This means only food energy from one trophic level can be used by the following levels. Explain what happens to the other 90%

Answer 13

Snake and frog example

-While the snake is hunting or looking for the frog, the frog is using up energy to hop around (energy that the snake can’t use)
-There are many frogs that the snake won’t be able to eat (meaning there is energy they won’t even be able to use)
-Even when the snake does manage to capture one frog, it does not (and can not) digest all the Frog’s energy

Question 14

Specific movements of carbon in its matter cycle - Lithosphere to Biosphere

Answer 14

o Lithosphere to Atmosphere ( carbon is released through decomposition of dead organic matter in the soil and through the metabolic processes of soil microbes
o -Atmosphere to Hydrosphere (Carbon is absorbed by the ocean and other bodies of water)
o -Hydrosphere to Biosphere (Carbon is absorbed by marine plants and animals during photosynthesis

Question 15

Impact on the carbon cycle from burning fossil fuels

Answer 15

Before there was more carbon in the lithosphere (the earth (ground) than the atmosphere (air). After burning fossil fuels, there is less carbon in the lithosphere and more in the atmosphere because more fossil fuels were being taken from the ground (lithosphere) and burned into the air (atmosphere)

Question 16

Could there be a food chain without herbivores, ominvores, and carnivores

Answer 16

(Food chains could exist (Producers to Decomposers -recycle,) they are about the flow of energy (Between the Producer and Decomposer) Thus even if herbivores, omnivores, carnivores were not in the picture, there would still be a food chain)

Question 17

Does the population size increase or decrease at higher trophic levels in the pyramid of numbers for all of your ecosystems? What might explain your data?

Answer 17

The population would decrease in higher trophic levels Because there is Less and less energy at each trophic level)

Question 18

What might happen to an ecological pyramid of numbers in a forest ecosystem if most of the deer were killed due to hunting by people and disease?

Answer 18

If most of the deer were killed, there would be a decrease in carnivore populations

(The deer represented energy source for the above trophic levels, thus the carnivore population will decrease, while the producers population will increase)

Question 19

Describe what would happen to an ecosystem if the decomposers disappeared?

Answer 19

If decomposers disappear, there would be no nutrient cycle, meaning the ecosystem would eventually run out of nutrients and stop working. (A bunch of dead organisms and stop nutrient cycle, meaning ecosystem will collapse. Because we have nothing to break down the decaying matter, and we don’t have a way to recycle nutrients)