4.2 Energy Flow

Question 1

What does photoautotrophic mean?

Answer 1

They use sunlight as a source of energy

Question 2

What are all green plants and some bacteria?

Answer 2

Photoautotrophic

Question 3

What is an essential source of energy for almost all communities?

Answer 3

Light

Question 4

What are the producers in a few ecosystems?

Answer 4

Chemoautotrophic bacteria

Question 5

What is chemoautotrophic?

Answer 5

Energy is derived from chemical processes

Question 6

How is light energy converted into chemical energy?

Answer 6

Via photosynthesis

Question 7

What is light energy used to do?

Answer 7

Make organic compounds from inorganic sources

Question 8

What happens to the organic compounds produced?

Answer 8

Heterotrophs eat them to get their chemical energy

Question 9

How are organic compounds broken down?

Answer 9

Via cell respiration

Question 10

What happens when organic compounds are broken down?

Answer 10

ATP is produced to fuel metabolic processes

Question 11

How does energy enter most ecosystem as?

Answer 11

Sunlight

Question 12

What converts sunlight into chemical energy?

Answer 12

Producers

Question 13

Where is the chemical energy stored?

Answer 13

In carbon compounds

Question 14

How is chemical energy transferred to heterotrophs?

Answer 14

Via feeding

Question 15

What is a trophic level?

Answer 15

The position an organism occupies within a feeding sequence

Question 16

What position in a feeding sequences do producers always occupy?

Answer 16

The first trophic level

Question 17

What position are primary consumers and why?

Answer 17

The second trophic level as they feed on producers

Question 18

What position do further consumers occupy?

Answer 18

Subsequent trophic levels like secondary and tertiary

Question 19

What is a food chain?

Answer 19

Showing the linear feeding relationships between species in a community

Question 20

What do arrows represent in food chains?

Answer 20

The transfer of energy and matter as one organism is eaten by another

Question 21

What direction do arrows point in food chains?

Answer 21

In direction of energy flow

Question 22

What is the first organism in a food chain?

Answer 22

A producer followed by consumers

Question 23

What can the energy stored in organic molecules be released to do?

Answer 23

Produce ATP

Question 24

What is the ATP from organic molecules used to do?

Answer 24

Fuel metabolic reactions needed for growth and homeostasis

Question 25

What is a by product of metabolic reactions?

Answer 25

Heat

Question 26

What happens to the heat by product of metabolic reactions?

Answer 26

It is released from the organism

Question 27

Where is some chemical energy lost to?

Answer 27

- Being excreted as faeces - Remains unconsumed as uneaten parts of the food - Respiration - Released as heat

Question 28

What are the three ways chemical energy produced by an organism can be converted?

Answer 28

Kinetic energy Electrical energy Light energy

Question 29

When would chemical energy be converted into kinetic energy?

Answer 29

During muscle contraction

Question 30

When would chemical energy be converted into electrical energy?

Answer 30

During the transmission of nerve impulses

Question 31

When is chemical energy converted into light energy?

Answer 31

Producing bioluminescence

Question 32

Why is heat released as a by product?

Answer 32

As living organisms cannot turn this heat into other forms of usable energy

Question 33

What happens to heat once it is released from the organism?

Answer 33

It is lost from the ecosystem

Question 34

Why do ecosystems require a continuous influx of energy from an external source?

Answer 34

As heat energy is lost from the ecosystem

Question 35

Why is the energy transformations process never 100% efficient?

Answer 35

Most of the energy is lost to the organism

Question 36

How efficient are energy transformations typically?

Answer 36

10%

Question 37

What does the amount of energy transferred depend on?

Answer 37

How efficiently organisms can capture and use energy?

Question 38

Why do higher trophic levels have less biomass?

Answer 38

As they store less energy as carbon compounds

Question 39

What is biomass?

Answer 39

The total mass of a group of organisms consisting of the carbon compounds contained in the cells and tissues

Question 40

How can scientists measure the amount of energy added to organisms as biomass?

Answer 40

Because carbon compound store energy

Question 41

What happens to biomass along food chains?

Answer 41

It diminishes with the loss of carbon dioxide, water and waste products to the environment

Question 42

Why are the number of potential trophic levels are limited?

Answer 42

Because energy and biomass is lost between each level of a food chain

Question 43

Why do higher trophic levels need to eat larger quantities ?

Answer 43

To obtain sufficient amounts of energy

Question 44

When will the trophic level become unviable?

Answer 44

If the energy required to hunt food exceeds the energy available from the food eaten

Question 45

What is a pyramid of energy?

Answer 45

A graphical representation of the amount of energy at each trophic level of a food chain

Question 46

In what units are pyramid of energy expressed?

Answer 46

Energy per area per timeq

Question 47

Why will pyramids never appear inverted?

Answer 47

As some of the energy stored in one source is always lost upon transfer

Question 48

What size should a level in a pyramid of energy be?

Answer 48

one tenth

Question 49

What will the bottom level of a pyramid of energy always be?

Answer 49

The producers

Question 50

What do the subsequent levels of a pyramid of energy represent?

Answer 50

Consumers