7.2

Question 1

What is the hydrosphere?

Answer 1

All of the water on Earth.

Question 2

What is the lithosphere?

Answer 2

The outermost layer of the Earth.

Question 3

What is the atmosphere?

Answer 3

The layer of gases surrounding the Earth.

Question 4

What is the biosphere?

Answer 4

All living things on Earth and their ecosystems.

Question 5

How do Earth’s four spheres relate to each other?

Answer 5

They interact and influence each other.

Question 6

What does the biosphere consist of?

Answer 6

Biota (all living things).

Question 7

What is the biosphere?

Answer 7

The layer in which life exists on Earth.

Question 8

What are biomes?

Answer 8

Regions influenced by environmental factors like latitude, temperature, and rainfall.

Question 9

What are ecosystems?

Answer 9

Smaller areas within biomes, defined by interactions among organisms in a particular environment.

Question 10

What is the troposphere?

Answer 10

The 1st layer of the atmosphere, closest to Earth, containing closely packed air particles. It makes up 75% of the atmosphere’s mass.

Question 11

What is the stratosphere?

Answer 11

The 2nd layer, about 55 km above Earth’s surface, containing the ozone layer, which absorbs UV radiation and allows visible light and IR through.

Question 12

What is the mesosphere?

Answer 12

The 3rd layer, with temperatures ranging from 0 to -90˚C, where meteors burn up as they enter Earth’s atmosphere.

Question 13

What is the thermosphere?

Answer 13

The 4th layer, 80-500 km from Earth, containing the ionosphere.

Question 14

What is the exosphere?

Answer 14

The outermost layer of the atmosphere, located 500 km or more from Earth.

Question 15

What is the hydrosphere?

Answer 15

The hydrosphere contains all the water on Earth, which moves through different states via the water cycle.

Question 16

What is the lithosphere?

Answer 16

The Earth’s rocky crust, consisting of igneous, sedimentary, and metamorphic rocks, and soil.

Question 17

How are biomes in the biosphere named?

Answer 17

Biomes are named based on their dominant type of vegetation.

Question 18

Are any biomes physically located within the lithosphere?

Answer 18

Yes, some biomes are physically located within the lithosphere.

Question 19

Where is carbon found in the hydrosphere?

Answer 19

As dissolved carbon dioxide.

Question 20

Where is carbon found in the lithosphere?

Answer 20

As coal, oil deposits, and rocks like limestone.

Question 21

Where is carbon found in the atmosphere?

Answer 21

As methane and carbon dioxide.

Question 22

Where is carbon found in living things?

Answer 22

As proteins, carbohydrates, and lipids.

Question 23

What does the carbon cycle show?

Answer 23

How carbon moves through the biosphere.

Question 24

How does carbon travel from the atmosphere to living things?

Answer 24

Carbon dioxide is absorbed by photosynthetic organisms like plants.

Question 25

What processes are vital in the carbon cycle?

Answer 25

Photosynthesis and cellular respiration.

Question 26

What is photosynthesis?

Answer 26

A process used by plants and other organisms to convert light energy into chemical energy, which can later fuel their activities.

Question 27

What is the chemical reaction for photosynthesis?

Answer 27

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (Carbon dioxide + water + sunlight → Glucose + oxygen)

Question 28

What do plants take in and produce during photosynthesis?

Answer 28

Plants take in carbon dioxide and water, and produce glucose and oxygen in the presence of sunlight.

Question 29

What does the nitrogen cycle explain?

Answer 29

How nitrogen moves through the biosphere.

Question 30

Why is nitrogen important?

Answer 30

1. Cells need it to make DNA and proteins (enzymes, hormones, etc.).
2. Plants need it to make chlorophyll for photosynthesis.

Question 31

How much nitrogen makes up the air?

Answer 31

Nitrogen makes up approximately 78% of the air.

Question 32

Can nitrogen in the air (N₂) be used directly by organisms?

Answer 32

No, nitrogen in the air needs to be changed through processes in the nitrogen cycle.

Question 33

What is fixation in the nitrogen cycle?

Answer 33

Fixation is the first step, where bacteria convert nitrogen into ammonium, making it usable by plants.

Question 34

What is nitrification?

Answer 34

Nitrification is the process where ammonium is changed into nitrates by bacteria, which plants can then absorb.

Question 35

What is assimilation in the nitrogen cycle?

Answer 35

Assimilation is how plants absorb nitrates from the soil into their roots, using the nitrogen in amino acids, nucleic acids, and chlorophyll.

Question 36

What is ammonification?

Answer 36

Ammonification is the decaying process where decomposers like fungi and bacteria turn nitrogen from dead plants and animals back into ammonium.

Question 37

What is denitrification?

Answer 37

Denitrification is when extra nitrogen in the soil is released back into the air by special bacteria.

Question 38

What does the phosphorus cycle represent?

Answer 38

How phosphorus moves from the lithosphere to the hydrosphere, through food chains, and back.

Question 39

Why is phosphorus important?

Answer 39

It is a key component of fertilizers, promoting plant growth, healthy root and shoot development, flower and seed production, and improving crop quality.

Question 40

What benefits does phosphorus provide to plants?

Answer 40

It promotes healthy root growth, early shoot growth, improved flower and seed production, and enhances the quality of fruit, vegetables, and grain crops.

Question 41

How does phosphorus differ from nitrogen in terms of climate change?

Answer 41

Phosphorus has no major gaseous form, so it has little impact on climate change.

Question 42

List 6 examples of human impacts on earth cycles.

Answer 42

Deforestation, Mining, Travel, GHG’s, increasing population, industrial wastes, Travel.