Photosynthesis

Q.

How would you test the presence of starch in leaves?

Q.

Explain carbon cycle with the help of a diagram. [5 MARKS]

Q.

The ultimate source of energy for all living organisms is the __ .

Q.

Test for starch in leaves

Q.

Identify the correct sequence of steps in the process of photosynthesis.

1. Splitting of water to 2H⁺ and [O] → Reduction of CO₂ → Absorption of light by Chlorophyll → Carbohydrate formation

2. Absorption of light by chlorophyll → Splitting of water to 2H⁺ and [O] → Reduction of CO₂ → Carbohydrate formation

3. Splitting of water to 2H⁺ and [O] → Absorption of light by Chlorophyll → Reduction of CO₂ → Carbohydrate formation

4. Absorption of light by Chlorophyll → Reduction of CO₂ → Splitting of water to 2H⁺ and [O] → Carbohydrate formation

Q. The ultimate source of energy for all living organisms is _______ .

1. Electricity
2. Water
3. Wind
4. Sun

Q.

What are the three factors that affect the rate at photosynthesis occur?

Q.

What is necessary for photosynthesis?

1. Chlorophyll

2. Sunlight

3. Carbon dioxide and water

4. All of the above

Q.

Difference between carbon, oxygen and chemical cycle

Q.

Carbon dioxide is released during photosynthesis.

1. True
2. False

Q.

The leaves of a plant are known as its 'food factories'.

1. False
2. True

Q. Some plants are green and have chlorophyll, even then they feed on insects for their survival. Why?

1. These plants can photosynthesise but require insects for nitrogen supplements.

2. These plants cannot photosynthesise, so they depend on insects.

3. These plants can photosynthesize but insects are just an additional food item.

4. These plants cannot absorb water required for photosynthesis so extracts water from insects.

Q.

Potatoes are generally brown in colour. But, we find some green areas on potatoes. Give reason.

Q. Main nutrients required by plants for their growth are nitrogen, phosphorus and .

Q. Which of the following equation sums up photosynthetic reaction most accurately?

1. $CO+H_{2}O\underset{chlorophyll}{\overset{light}{\to }}C{H}_{2}O+O_2$
   
2. $6C{O}_2+6H_{2}O\underset{chlorophyll}{\overset{light}{\to }}{C}_6{H}_{12}{O}_6+6O_2$
   
3. $6C{O}_2+12H_{2}O\underset{chlorophyll}{\overset{light}{\to }}{C}_6{H}_{12}{O}_6+6O_2+6H_{2}O$
   
4. $6C{O}_2+12H_{2}O\underset{chlorophyll}{\overset{light}{\to }}{C}_6{H}_{12}{O}_6+6H_{2}O$

Q.

Discuss the return of carbon dioxide back to the atmosphere.

Q.

The process through which carbondioxide is taken up by the plants is________.

1. Greenhouse effect
2. Photosynthesis
3. Combustion
4. Carbon cycle

Q.

The end product of photosynthesis which is a carbon compound is ____ and is converted into ____.

1. deoxyribose ; glycogen

2. glucose; glycogen

3. ribose; starch

4. glucose; starch

Q. Assertion :Brian-dead patient lying in coma has no self-consciousness. Reason: All living phenomenon are due to underlying interactions.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

Appu focused a section of leaf under the microscope and observed the following image. Statements below list characteristics of the labeled parts. Based on the statements choose the correct option.

Statement 1-(iii) helps to regulate transpiration.

Statement 2-(ii) allows only entry of water vapour.

Statement 3-(i) is essential for photosynthesis.

Statement 4-(iii) closes completely in the morning.

1. Statements 1, 2, 3 and 4 are correct.

2. Statements 1 and 3 are correct.

3. Statements 2, 3 and 4 are correct.

4. Statements 1 and 2 are correct.

Q.

Instead of using KOH, ____ can also be used to detect the presence of CO₂ during photosynthesis.

Q.

Oxygen is returned to the atmosphere mainly by ______.

1. photosynthesis

2. burning of fossil fuel

3. decomposition

4. respiration

Q.

Which pigment is necessary in order for plants to convert carbon dioxide and water, in the presence of sunlight, into oxygen and glucose?

1. Chlorophyll

2. Carotenoids

3. Haemoglobin

4. Melanin

Q.

What is function of stomata ?

Q.

(a) State the way by which oxygen enters in the atmosphere.

(b) State the ways by which oxygen is removed from the atmosphere.

(c) How does the percentage of oxygen in the atmosphere remain constant, inspite of the fact that a large amount of it is used for combustion and respiration.

Q.

Question 24
Oxygen is returned to the atmosphere mainly by:

(a) burning of fossil fuel
(b) respiration
(c) photosynthesis
(d) fungi

Q.

Two potted green plants of the same kind were taken to perform an experiment. One of them was kept in a dark room, while the other one was kept in sunlight for 3–4 days. A leaf from each of the plant was taken to perform the iodine test. Which of the leaves turned blue-black in colour? [5 MARKS]

Q.

Name the two important biological processes in which air is essential.

Q.

Tiny pores on the surface of leaves are:

1. Lamina

2. Stomata

3. Chlorophyll

4. Leaf stalk

Q.

Which of the following is not a good source of leaf peel?

1. Lily

2. Petunia

3. Cactus

4. Bryophyllum