Significance of Photosynthesis

Q. Which of the statements is/are true regarding Global Warming?

1. Global warming mainly results from an increase in the levels of greenhouse gases such as carbon dioxide and methane in the atmosphere.
2. Carbon monoxide dissolves in water to form carbonic acid.
3. Global warming reduces pH levels in the oceans.
4. All of the above

Q.

If some leaves were plucked and then iodine test was performed on them, what would be the result?

Q. Question 5 (d)
Solution in brief.
What are the causes and consequences of deforestation?

Q.

Global warming is caused only by natural factors.

1. False

2. True

Q. Question 2
Which one of the following changes may occur due to desertification?

(a) Decrease in atmospheric temperature.
(b) Increase in water holding capacity of soil.
(c) Increased chances of floods.
(d) Conversion of fertile land into a desert.

Q.

The earth has an average temperature of 33 degree celcius 33°C which makes life possible on earth. This is due to:

1. global warming
2. deforestation
3. soil erosion
4. greenhouse effect

Q.

Cyanobacteria are consumers.

1. True
2. False

Q. Which of the following statement defines the ecosystem?

1. The abiotic component of a habitat.
2. The part of the earth that is inhabited by biotic components.
3. A community of organisms interacting with each other.
4. A community of organisms interacting with the environment they live in.

Q.

Presence of starch in leaves is confirmed by which test?

Q.

Match the numbers with the gases.

1. 1- oxygen​, 2- carbon dioxide

2. 1- oxygen​, 2- carbon monoxide

3. 1- ​carbon monoxide, 2- oxygen​

4. 1- carbon dioxide, 2- oxygen

Q. What is / are the likely consequence of the activity as shown in the figure given below?

1. Carbon dioxide in the air increases
2. Destruction of habitats
3. Mineral salts in the soil are washed away
4. All of these

Q.

Which of the following is mainly responsible for global warming?

1. Carbon dioxide

2. Nitrogen

3. Oxygen

4. Sulphur

Q.

To test the presence of starch _________ solution is used.

Q.

Which of the following are the producers that do not depend on sunlight for the preparation of food?

1. Trees

2. Sulfur bacteria

3. Blue-green algae

4. Shrubs

Q.

Destarching makes a leaf free from:

1. Chlorophyll

2. Cellulose

3. Glucose

4. Starch

Q.

Which of these are the natural causes of deforestation?

1. Forest fires

2. Severe droughts

3. Burning of fossil fuels

4. Agriculture

Q.

How do humans use plants?

Q. Reforestation is essential

1. Most of the forests have been lost in tropical areas
2. Ozone in upper part of atmosphere is harmful to animals
3. Greenhouse effect is a natural phenomenon
4. Eutrophication is a natural phenomenon in fresh water bodies

Q.

Which of these are not directly affected by deforestation?

1. Difference in habitats

2. Fish will not be able to grow

3. Global Warming

4. Number of trees

Q.

Iodine solution is used for the presence of starch.

1. True
2. False

Q. Global warming is in the temperature of Earth's .

1. drop
2. maintenance
3. rise
4. sea level
5. atmosphere

Q.

Name the simple sugar found in plant tissues which is also a product of photosynthesis.

1. Amino acids

2. Fructose

3. Glucose

4. Sucrose

Q. Planting large number of trees result in :

1. an increase in oxygen production
2. an increase in carbon dioxide production
3. a decrease in oxygen production
4. a decrease in carbon dioxide production

Q.

What does the graph depict?

1. A rise in the global average temperature
2. An approximate rise of 0.9⁰ C over 140 years
3. Both A and B are true
4. Neither A nor B is true

Q. Carbon dioxide causes global warming as it traps _____________. ​

1. water
2. heat

Q.

Which of these following statement is the correct meaning of the term 'global warming'?

1. Slow and steady rise in the earth's surface temperature

2. Rapid rise in the earth's surface temperature

3. Slow and steady decrease in the earth's surface temperature

4. Rapid decrease in the earth's surface temperature

Q.

Which of the following is not the cause of global warming?

1. Use of CFCs

2. Burning of fossil fuels

3. Afforestation

4. Greenhouse effect