Ecosystems

Question 1

Define ecosystem

Answer 1

Describes the interactions between populations and the abiotic factors in their habitat

Question 2

Give some examples of ecosystems

Answer 2

1) the human large intestine
2) a puddle
3) tropical rainforests
4) the sea

Question 3

What is the source of energy for all ecosystems

Answer 3

The sun- sunlight is the source of photosynthesis

Question 4

Define Habitat

Answer 4

the place an organism lives

Question 5

Define community

Answer 5

refers to the interacting of two or more populations in the same habitat at the time

Question 6

Define biomass

Answer 6

The mass of biological material in living, or recently living organisms- biomass moves through ecosystems via trophic levels.

Question 7

Define trophic level

Answer 7

the number of times that energy (biomass) has been transferred between the sun and successive organisms along the food chain
OR
the position and organism holds in the food chain

Question 8

Why is not all sunlight absorbed by plants used in biomass of plant tissues

Answer 8

1) doesn’t hit the plant
2) misses photosynthetic regions of the plants
3) is reflected off of the plant
4) passes through the leaf, transmission

Question 9

What are detrivores and decomposers

Answer 9

1) organisms, such as earthworms, which feed or small fragments of dead organic matter
2) microbes, such as bacteria, that obtain nutrients from dead organisms or organic waste- completing the process of decomposition started by detrivores

Question 10

Describe what a food chain shows

Answer 10

The transfer of biomass through different organisms
starting at primary consumers moving onto primary, secondary, etc consumers
as biomass is passed through trophic energy is lost

Question 11

What do food chains not show

Answer 11

1) detrivores and decomposers which are often greater biomass than other consumers
2) omnivores or organisms feeding at the same trophic level

Question 12

What determines the length of a food chain

Answer 12

1) the more energy entering at T1 the longer it will be
2) the efficiency of transfer between levels
3) larger ecosystems= longer

Question 13

Define gross primary productivity

Answer 13

The rate of production of chemical energy in organic molecules by photosynthesis in a given area in a given time.

Question 14

Define Net primary productivity

Answer 14

Energy in the plant’s biomass which is made available to primary consumers

Question 15

How is net primary productivity measures

Answer 15

GPP- respiration= NPP

Question 16

Define primary productivity

Define secondary productivity

Answer 16

1) the rate at which energy is converted by producers into biomass
2) the rate at which consumers convert the chemical energy of their food into biomass

Question 17

Why is energy lost through the food chain

Answer 17

1) Energy in molecules which are egested
2) Energy lost as heat
3) Energy remains in moleucles of uneaten parts