5th - Science Unit 5 Lesson 5 Revised

Question 0

What does soil contain?

Answer 0

Nutrients and microorganisms

Question 1

Is a mixture of rock and bits of once living parts of plants and animals that cover most of Earth’s land masses?

Answer 1

Soil

Question 2

What factors pollute soil?

Answer 2

Chemicals, biological materials or trash

Question 3

Name some examples of soil pollution.

Answer 3

1. Can occur when substances such as oil or gas spills or is not disposed of properly.
2. Can occur when farmers apply herbicides and pesticides used to control weeds and insects reach the soil.
3. Can occur when litter is disposed of in landfills that are not properly built allowing harmful substances to leak into the soil.

Question 4

What are consequences of soil pollution?

Answer 4

1. Harmful substances can leak into soil and then be washed into streams and rivers by the rain.
2. When even small amounts of pollution stay in the soil they can cause changes to the soil harming the ecosystem. (Killing or harming the insects and decomposers - if decomposers do not return nutrients to the ecosystem, producers cannot grow.)
3. Polluted soil will often produce smaller crops yields.
4. Toxic materials or dangerous biological materials can even pose health risks to humans and other organisms.

3.

Question 5

What holds the gases we need to stay alive?

Answer 5

Earth’s atmosphere

Question 6

What are the gases in the Earth’s atmosphere?

Answer 6

Oxygen, carbon dioxide and nitrogen

Question 7

How are the gases in the Earth’s atmosphere used?

Answer 7

1. Plants use carbon dioxide to make food.
2. Animals and plants use oxygen to get energy
3. Some bacteria turn nitrogen into chemicals that plants use to grow.

Question 8

What are factors of air pollution?

Answer 8

Particles of polluting materials build up in the air:

1. They are produced when fossil fuels or trash are burnt.
2. Dust from plowed fields, construction sites or mines.
3. Chemicals that are produced by factories.

Question 9

What are consequences of air pollution?

Answer 9

1. Smog (a yellow haze in the air over cities) causes eye irritation and makes it difficult to breathe.
2. Ozone holes (caused by chemicals in aerosol cans and air conditioners escape into the atmosphere damaging the ozone layer - these are no longer used today) cause increased chances of getting skin cancer.
3. Acid rain (caused by smoke and gases that pour into the air from factories that combine with rain) can kill trees and wear away stone building and statues.

Question 10

What are some signs that water is polluted?

Answer 10

1. It might smell
2. Have a strange color
3. Be cloudy
4. Have dead fish in it

But you can’t always tell, it might look clear and still contain chemicals or harmful organisms that could make you sick.

Question 11

Name some ways that fresh water is contaminated.

Answer 11

1. Farmers and homeowners use different kinds of chemicals to help their crops and lawns grow.
2. People use chemicals to kill organisms that are harmful to plants.
3. As water flows over streets can pick up contaminants such as salt, spilled motor oil and trash.
4. Fertilizer and animal waste from farms can also wash into rivers and streams. These substances have high amounts of nutrients that can lead to algae blooms. When algae blooms die they use up oxygen dissolved in the water, killing fish.

Question 12

Name two of the most important laws passes by the United States government to prevent water pollution.

Answer 12

1974 Safe Drinking Water Act and the 1977 Clean Water Act

Question 13

What law sets the sulks that communities across the United States must follow to keep drinking water safe and clean?

Answer 13

Safe Drink Water Act of 1974

Question 14

What law made it illegal to throw pollutants into surface waters such as streams, rivers, lakes and oceans?

Answer 14

Clean Water Act of 1977

Question 15

Who changes ecosystems by introducing new species?

Answer 15

Humans

Question 16

Explain how the introduction of zebra mussels into freshwater ecosystems in the U S changed it.

Answer 16

In a food web, organisms compete with each other for food and other resources. Zebra mussels are tough competitors - they reproduce quickly, have huge appetites and can consume large amounts of food. Some native species cannot compete. As a result, these native species have declined in number.

Question 17

What nonnative species caused problems for Louisiana?

Answer 17

Nutria

Question 18

Why were nutria brought to Louisiana? What did they do?

Answer 18

Nutria were brought to Louisiana for their fur. But their dense populations and feeding habits cause damage to crop fields and coastal wetlands.

Question 19

What nonnative species caused damage to the wetlands by clogging waterways and reducing water quality by blocking sunlight and depleting oxygen?

Answer 19

Water Hyacinths

Question 20

What is the process of keeping populations at desired levels for their ecosystems?

Answer 20

Wildlife management

Question 21

How can hunting affect ecosystems?

Answer 21

Unregulated hunting can have a negative effects on animal populations but regulated hunting can be beneficial to populations and ecosystems.

Question 22

How does regulating hunting help ensure that populations maintain their carrying capacity?

Answer 22

Helps ensure that populations do not reach levels that can be harmful to the ecosystem. Does not allow for overpopulation

Question 23

What do wildlife managers do?

Answer 23

Track the number of organisms in a population and how many are removed by hunting and trapping. They establish regulations to ensure that the number of animals hunted keeps the population in balance.