Bloc 3 (P26-P29)

Question 1

What is an ecosystem?

Answer 1

An ecosystem is a geographic entity consisting of two components in constant interaction: the abiotic component (biotope) and the biotic community (biocenosis).

The relationship can be summarized as: Ecosystem = biotic factors + abiotic factors.

Question 2

What are the two main components of an ecosystem?

Answer 2

1) Abiotic component (biotope)
2) Biotic community (biocenosis)

Question 3

Define trophic level.

Answer 3

The trophic level refers to the position of individuals in the food chain concerning energy flow.

Question 4

True or False: An ecosystem is a static entity.

Answer 4

False

Ecosystems are dynamic structures involving continuous exchanges between components.

Question 5

What are biogeochemical cycles?

Answer 5

Biogeochemical cycles are the circulation of essential biogenic elements (like carbon, oxygen, nitrogen, etc.) within ecosystems and the biosphere.

Question 6

What is the role of energy flow in an ecosystem?

Answer 6

Energy flow sustains the ecosystem autonomously by circulating various chemical elements among biotic and abiotic components.

This process is known as the cycle of matter.

Question 7

List the three functional categories of biocenosis in an ecosystem.

Answer 7

1) Producers
2) Consumers
3) Decomposers

Question 8

What are consumers in an ecosystem?

Answer 8

Consumers are organisms that require biochemical energy from other living beings to meet their nutritional needs.

All consumers are heterotrophs.

Question 9

Fill in the blank: Consumers that primarily eat plants are called _______.

Answer 9

primary consumers (herbivores)

Question 10

What are secondary consumers?

Answer 10

Secondary consumers are organisms that eat primary consumers, typically herbivores.
They can be carnivores or omnivores.

Question 11

Define tertiary consumers.

Answer 11

Tertiary consumers are carnivores that eat secondary consumers.
They are often referred to as higher-level predators.

Question 12

What are super predators?

Answer 12

Super predators are apex predators that have no natural enemies and are at the top of the food chain.

Question 13

What are decomposers?

Answer 13

Heterotrophs that transform dead organic matter into mineral elements.

Question 14

What are détritivores?

Answer 14

Organisms that ingest coarse dead organic matter.
Examples include earthworms, vultures, flies, crows, and dung beetles.

Question 15

What are saprophages?

Answer 15

Organisms such as fungi and bacteria that degrade dead organic matter.

Question 16

What is the ecological function of saprophages?

Answer 16

To decompose various dead organic materials, both plant and animal, and fully mineralize them.

Question 17

Fill in the blank: Decomposers are responsible for the _______ of organic matter.

Answer 17

recycling

Question 18

True or False: Decomposers play a role in returning matter to the earth.

Answer 18

True

Question 19

What is a chain alimentaire?

Answer 19

A representation of the transfer of solar energy from producers to consumers and does not include decomposers.

Question 20

What is a niveau trophique?

Answer 20

The position occupied by an organism in the chain alimentaire

Question 21

Who is always the first organism in a chain alimentaire?

Answer 21

A producer (or autotroph)

Question 22

How are omnivores classified in terms of consumers?

Answer 22

As secondary consumers

Question 23

True or False: Decomposers are typically represented in a chain alimentaire.

Answer 23

False

Decomposers are usually not included in the representation.

Question 24

Fill in the blank: The chain alimentaire is a representation of the transfer of solar energy from _______ to consumers.

Answer 24

[producers]

Question 25

What is an ‘espèce clé’?

Answer 25

A key species that has a significant impact on an ecosystem.

Question 26

What happens if a key species disappears from an ecosystem?

Answer 26

The effects will be multiple and devastating, disrupting all ecological relationships in the food web.

Question 27

Define ‘espèce envahissante’.

Answer 27

An exotic species that rapidly colonizes an ecosystem.

Question 28

Why do invasive species dominate an ecosystem?

Answer 28

They lack predators to control their population.

Question 29

What is the competitive effect of invasive species on native species?

Answer 29

Invasive species become very competitive against native species occupying the same ecological niche.

Question 30

Fill in the blank: An invasive species can exterminate _______.

Answer 30

native species.

Question 31

Give examples of invasive species.

Answer 31

• Zebra mussels
• Norway maples
• Asian lady beetles