CH.20.1&20.2: energy flow/food chains and food webs

Question 1

Principal source of energy

Answer 1

Sun

Question 2

Energy flow is not a cycle

Answer 2

it starts from the sun and then that energy is harnessed by plants which are eaten by animals which are eaten by other animals

Question 3

At each step of the food chain, what happens to the energy?

Answer 3

They are lost to the environment

Question 4

EPPST

Answer 4

Energy->Producer->Primary consumer->Secondary consumer->Tertiary consumer

Question 5

flow of energy from one organism to the next (beginning with a producer)

Answer 5

food chain

Question 6

a network of interconnected food chains showing the energy flow through part of an ecosystem

Answer 6

food web

Question 7

• (an organism that) makes its own organic nutrients
• usually using the energy from the sunlight(photosynthesis)

Answer 7

producer

Question 8

(an organism that) gets its energy by feeding on other organisms

Answer 8

Consumer

Question 9

(animal that) gets its energy by eating plants

Answer 9

<Herb>ivore
</Herb>

Question 10

(animal that)gets its energy by eating other animals

Answer 10

<Carn>ivore
</Carn>

Question 11

(an organism that) gets its energy from dead or waste organic matter

Answer 11

decomposer

Question 12

What is ecosystem?

Answer 12

• a unit
• contain all(organism, environment)
• interact each other
• in the same area

Question 13

the position of an organism in a food chain food web or pyramid of biomass, numbers or energy

Answer 13

Trophic level

Question 14

Why food chains usually have ↓than 5 trophic levels

Answer 14

it’s inefficient
- sun produces light, less than 1% of the energy falls onto leaves
- producers ‘fix’ only about 5-8% of that energy, because of: <transmission>, <reflection>, and <incorrect>
- primary consumer only gets between 5-10% because someparts are indigestible(not eating the whole plant)
- secondary consumer gets between 10-20% because animal matter is more digesible and has a higher energ value
- at each level, heat is lost by respiration</incorrect></reflection></transmission>

Question 15

Why eating plants is more efficient than eating animals?

Answer 15

• must feed the animal a lot of plant material to get sufficient amount of energy
• (in the process of raising an animal), animal/plants lose energy to environment –> does not use up all the plant material

Question 16

Food chains can be built up into complex…

Answer 16

food webs

Question 17

What is the difference between food chains and food webs?

Answer 17

Food webs have <branches>, chains never do</branches>

Question 18

In a pyramid of numbers, what does the length of each bar represent?

Answer 18

number of organisms (at each trophic level in a specified area)

Question 19

compares the number of organisms (at each trophic level)

Answer 19

Pyramid of numbers

Question 20

(compares) the mass of biologial material

Answer 20

Pyramid of biomass

Question 21

compares the amount of energy passing through (each trophic level over a period of time)

Answer 21

Pyramid of energy