UNIT 7 ck12’s 6.3-6.4

Question 1

What do food chains and food webs represent?

Answer 1

Feeding relationships in ecosystems.

Question 2

What is the primary function of food chains?

Answer 2

To model how energy and matter move through ecosystems.

Question 3

What does a food chain represent?

Answer 3

A single pathway by which energy and matter flow through an ecosystem.

Question 4

True or False: Food chains are always complex representations of nature.

Answer 4

False.

Question 5

Fill in the blank: Food chains are generally _______ than what really happens in nature.

Answer 5

simpler.

Question 6

What is a characteristic of most organisms in relation to food chains?

Answer 6

Most organisms consume and are consumed by more than one species.

Question 7

What does a food web represent?

Answer 7

Multiple pathways through which energy and matter flow through an ecosystem

Question 8

What does a food web include?

Answer 8

Many intersecting food chains

Question 9

True or False: Most organisms in a food web eat and are eaten by only one species.

Answer 9

False

Question 10

Fill in the blank: A food web demonstrates that most organisms eat and are eaten by _______.

Answer 10

more than one species

Question 11

What does a food web represent?

Answer 11

Multiple pathways through which energy and matter flow through an ecosystem

Question 12

What does a food web include?

Answer 12

Many intersecting food chains

Question 13

True or False: Most organisms in a food web eat and are eaten by only one species.

Answer 13

False

Question 14

Fill in the blank: A food web demonstrates that most organisms eat and are eaten by _______.

Answer 14

more than one species

Question 15

What are the feeding positions in a food chain or web called?

Answer 15

Trophic levels

Trophic levels indicate the position of organisms in a food chain or web based on their feeding relationships.

Question 16

What is the 1st trophic level?

Answer 16

Producer

Producers make their own food through processes like photosynthesis.

Question 17

What is the 2nd trophic level?

Answer 17

Primary Consumer

Primary consumers are organisms that consume producers.

Question 18

What is the 3rd trophic level?

Answer 18

Secondary Consumer

Secondary consumers eat primary consumers.

Question 19

What is the 4th trophic level?

Answer 19

Tertiary Consumer

Tertiary consumers consume secondary consumers.

Question 20

What do producers do?

Answer 20

Make their own food

Producers, like plants, create food through photosynthesis.

Question 21

Give an example of a primary consumer.

Answer 21

Mice

Mice consume plant seeds, thus classified as primary consumers.

Question 22

Give an example of a secondary consumer.

Answer 22

Snakes

Snakes eat primary consumers like mice.

Question 23

Give an example of a tertiary consumer.

Answer 23

Hawks

Hawks eat secondary consumers such as snakes.

Question 24

True or False: All food chains and webs have at least two or three trophic levels.

Answer 24

True

Food chains and webs typically consist of multiple trophic levels.

Question 25

What is the maximum number of trophic levels generally found in food chains?

Answer 25

Four ## Footnote Generally, food chains do not exceed four trophic levels.

Question 26

Fill in the blank: Humans are primary consumers when they eat _______.

Answer 26

plants ## Footnote Humans consume vegetables, classifying them as primary consumers.

Question 27

Fill in the blank: Humans are secondary consumers when they eat _______.

Answer 27

cows ## Footnote When humans consume cows, they act as secondary consumers.

Question 28

Fill in the blank: Humans are tertiary consumers when they eat _______.

Answer 28

salmon ## Footnote Eating salmon classifies humans as tertiary consumers.

Question 29

What is the general percentage of energy passed from one trophic level to the next?

Answer 29

About 10 percent ## Footnote This percentage reflects the energy transfer efficiency in ecosystems.

Question 30

What happens to the remaining 90 percent of energy in a trophic level?

Answer 30

It is used for metabolic processes or given off to the environment as heat ## Footnote This loss of energy occurs due to various biological functions and thermodynamic principles.

Question 31

Why are there rarely more than four trophic levels in a food chain or web?

Answer 31

Due to insufficient energy to support additional levels ## Footnote The energy loss at each level restricts the number of levels that can be sustained.

Question 32

What is represented by the ecological pyramid in relation to trophic levels?

Answer 32

The flow of energy through different trophic levels ## Footnote The ecological pyramid visually depicts energy distribution and loss in an ecosystem.

Question 33

Fill in the blank: Energy is passed up a food chain or web from lower to higher _______.

Answer 33

trophic levels ## Footnote Trophic levels categorize organisms based on their position in the food chain.

Question 34

True or False: There can sometimes be a fifth trophic level in a food chain or web.

Answer 34

True ## Footnote However, this is rare due to energy limitations.

Question 35

What do ecological pyramids demonstrate?

Answer 35

The decrease in energy, biomass, or numbers within an ecosystem

Question 36

What is biomass?

Answer 36

The total mass of organisms at a trophic level

Question 37

What happens to the number of organisms at higher trophic levels?

Answer 37

There are usually fewer organisms at higher trophic levels

Question 38

How does the size of organisms change at higher trophic levels?

Answer 38

Organisms tend to be larger in size at higher trophic levels

Question 39

What is the relationship between biomass and trophic levels?

Answer 39

There is a decrease in biomass from lower to higher trophic levels

Question 40

Fill in the blank: Biomass is the total mass of organisms at a _______ level.

Answer 40

trophic

Question 41

True or False: Higher trophic levels have more biomass than lower trophic levels.

Answer 41

False