Ecology and the Environment

Question 1

Population

Answer 1

All the organisms of one species living in a particular habitat

Question 2

Community

Answer 2

All organisms of a species found in a particular area at a certain time

Question 3

Habitat

Answer 3

The palace where organisms live

Question 4

Ecosystem

Answer 4

A community of living organisms together with their non-living environment

Question 5

Quadrats help us to:

Answer 5

1. Find the number of quadrats that contain the organism (frequency)
2. Find the number of organisms per m2 (density)
3. Estimate the number of each organism in the total area

Question 6

Using Quadrats:

Answer 6

1. Use quadrats to count the daises
2. First make a pair of the axis that covers the area
3. Then, using a random number generator, get a pair of numbers and use then for coordinates
4. Place the bottom left corner of the quadrat on the coordinates, and count the daises in it
5. Take 10 samples and find the average

Question 7

Biodiversity

Answer 7

The amount of variation shown by species in an ecosystem is called the biodiversity of the ecosystem.

Question 8

Biotic Factor (Living Factor)

Answer 8

A biological factor affecting an ecosystem

Question 9

Biodiversity Measurement

Answer 9

1. The number of species present (richness)

2. The relative abundance of each species (evenness).

Question 10

Producers

Answer 10

Plants that photosynthesize. They supply the energy for the ecosystem

Question 11

Consumers

Answer 11

Animals that eat the plants or other animals

Question 12

Deomposers

Answer 12

Bacteria or fungi that digest decaying/dead material in order to recycle nutrients

Question 13

A Physical Environment

Answer 13

This includes all the non-biological components (abiotic factors). The water, soil, temperature, etc.

Question 14

A Physical Environment

Answer 14

This includes all the non-biological components (abiotic factors). The water, soil, temperature, etc.

Question 15

Pyramids of Numbers

Answer 15

The organisms are plotted as separate blocks. The size of each block is related to the number of organisms. The producer always goes at the base, with each successive tropic level above it.

Question 16

Pyramids of Biomass

Answer 16

Biomass is the total amount of living material in an organism. It is quite hard to measure, but it produces more useful results. The easiest way to do it is to multiply the number at each level by the dry mass (mass without water) of one of the organisms.

Question 17

Pyramids of Energy Flow

Answer 17

Only about 10% of the energy entering a trophic level is passed on. Therefore energy is lost at each trophic level and it reduces the number of trophic levels.

Question 18

Reasons for Energy Loss

Answer 18

• Materials not eaten by consumer
• Materials not digested by consumer, but is passed out as waste (feces)
• Energy used by the consumer for movement
• Energy used by the consumer in body metabolic process
• Energy used in generating heat
• Energy lost in the urine

Question 19

Carbon Cycle

Answer 19

There is CO2 in the air and the trees absorb and release carbon through photosynthesis and respiration.
Animals also respire which releases CO2 back into the air.
From the trees and animals, decomposers release the carbon back into the air through respiration.
The trees and animals also go through fossilzation and turn into fossil fuels. The fossil fuels undergo combustion which releases carbon back into the atmosphere.