Ch 23 Practice Flashcards Preview

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Flashcards in Ch 23 Practice Deck (23):
1

Organisms that undergo photosynthesis make food which other organisms consume; a photosynthetic organism is a _____.

Producer

2

In the carbon cycle, organisms return carbon dioxide to the atmosphere through the process of cellular ______.

Respiration

3

Food chains generally consist of only three or four steps due to the loss of ______ between trophic levels.

Energy

4

A heterotroph that breaks down organic matter into inorganic nutrients that are recycled in the environment is called a ______.

Decomposer

5

Nitrogen can be a nutrient that limits growth in an ecosystem because the plentiful nitrogen in the atmosphere is:

In a form that is unusable to most organisms

6

An organism that cannot synthesize organic compounds from inorganic substances and therefore must consume organic food is called a(n) ______, or consumer.

Heterotrophs

7

______ are underground rock layers that hold water and are recharged by seepage from rain or melting snow.

Aquifers

8

What factors determine an organism's niche in an ecosystem?

• How an organism gets its food
• What an organism eats
• How the organism interacts with other populations in the same community

9

A(n) ______ is an organism that can use energy and inorganic nutrients to produce organic nutrients.

Autotroph

10

Phosphates are required by organisms to build which of the following molecules?

• ATP
• Phospholipids
• Nucleic acids

11

The air, land, and water that contains living organisms on Earth is called the

Biosphere

12

IN aquatic ecosystems, the exchange of carbon dioxide with the atmosphere is indirect because carbon dioxide from the atmosphere enters the water as ______ ions.

Bicarbonate

13

Tertiary consumers can also be called top

Predators

14

1st trophic level

Trees

15

2nd trophic level

Herbivores/primary consumers

16

3rd trophic level

Carnivores/secondary consumers

17

Ecological ______ can sometimes be used to depict large energy losses between successive trophic levels.

Pyramid

18

What chemicals are reactants for the process of photosynthesis?

• Carbon dioxide
• Water

19

Aquatic ecosystems are divided into two groups: those composed of ______ water (rivers, lakes, and ponds) and those composed of ______ water (marine ecosystems).

Fresh, salt

20

Certain cyanobacteria, some free-living bacteria in the soil, and bacteris within root nodules are capable of

Nitrogen fixation

21

In what ways are inorganic nutrients made available to producers>

• Physical processes, such as the weathering of rocks
• The action of decomposers

22

Most of the organic nutrients used by all organisms are produced by

Photosynthetic organisms

23

What are the two fundamental phenomena of ecosystems?

• Energy flow
• Nutrient cycling