Selina solutions for कन्साइस बायोलॉजी [अंग्रेजी] कक्षा १० आईसीएसई chapter 6 - Photosynthesis [Latest edition]

Answer the following in “Yes” or “No”

All parts of a green plant carry out photosynthesis

Answer the following in “Yes” or “No”

All green parts of a plant carry out photosynthesis.

Answer the following in “Yes” or “No”

Photosynthesis is the only biological process that releases oxygen into the air.

Answer the following in “Yes” or “No”

Out of nine types of chlorophylls, chlorophyll a and b are the most abundant.

Answer the following in “Yes” or “No”

Too much light destroys chlorophyll.

Answer the following in “Yes” or “No”

No transpiration occurs during photosynthesis.

Answer the following in “Yes” or “No”

During sunlight, the guard cells turn flaccid to open the stomata.

1. Write the overall summary of the chemical equation of photosynthesis.
2. Which single substance in the above equation is repeated in raw material as well as reproduced as an end product?

What is the source of oxygen released in photosynthesis - CO₂ or H₂O?

What happens in photolysis?

Dark reaction involves utilisation of CO₂ in producing C₆H₁₂O₆ (glucose). Why is this phase called dark reaction?

Glucose produced during photosynthesis is soon polymerised into starch. What does polymerisation mean?

Why is it better to call the dark phase of photosynthesis as “light-independent phase”?

How do the following favour increased photosynthesis?

Large surface area of the leaf.

How do the following favour increased photosynthesis?

Thinness of the leaf.

How do the following favour increased photosynthesis?

More numerous stomata.

Name the three end-products of photosynthesis and mention the fate of each of them in the plant.

If we keep on increasing CO₂ concentration in the air, will the rate of photõsynthesis also keep on increasing in direct proportion?

Yes/No. Explain.

Why is it necessary to destarch the leaves of a plant before performing an experiment on photosynthesis?

Why do we perform the iodine test?

What chemical do you use to remove CO₂ from inside a flask in certain experiments on photosynthesis?

All food chains start with a plant. Why is this so?

The honey bee produces honey. In terms of the food chain, is the honey bee a producer or a consumer?

Chlorophyll is located in ______.

Which of the following is not applicable to the process of photosynthesis?

The colour of VIBGYOR spectrum, which is reflected by chlorophyll, is ______.

The basic functional unit of solar energy which is absorbed by the pigment chlorophyll is ______.

The molecules of water split during ______.

The granum is a pile of many ______.

Which of the following is used to remove chlorophyll from the leaves?

The raw material which is reduced during photosynthesis is ______.

The optimum temperature for the process of photosynthesis is ______.

The conversion of several glucose molecules into starch is termed as ______.

Assertion (A): Photosynthesis occurs in all parts of a green plant.

Reason (R): Chlorophyll is the green pigment which traps solar energy during daytime.

Assertion (A): Guard cells regulate the opening and closing of the stomatal aperture.

Reason (R): Guard cells contain chloroplasts and are mostly located on the lower surface of the leaves. Other cells of the lower epidermis do not contain chloroplasts.

Assertion (A): Palisade cells of mesophyll are loosely arranged towards the lower epidermis of a dorsiventral leaf.

Reason (R): Palisade cells contain the maximum amount of chlorophyll, trap solar energy and help in the process of photosynthesis.

Assertion (A): Phosphorylation occurs in all organisms only during the process of respiration.

Reason (R): Photophosphorylation is the process during which ADP combines with inorganic phosphate (iP) and produces ATP.

Assertion (A): A plant should be placed in dark for 24 to 48 hours before using it for experiments on photosynthesis.

Reason (R): During this period, all the starch from the leaves, is either utilized in the process of respiration or stored in the storage organs.

Name the following:

The category of organisms that prepare their own food from basic raw materials.

Name the following:

The kind of plastids found in the mesophyll cells of the leaf.

Name the following:

The compound which stores energy in the cells.

Name the following:

The first form of food substance produced during photosynthesis. 

Name the following:

The source of carbon dioxide for aquatic plants. 

Name the following:

The part of chloroplast where the dark reaction of photosynthesis takes place.

Given below are groups of terms. The first pair indicates the relationship between the two terms. Complete the second pair accordingly.

Chlorophyll : Magnesium : : Haemoglobin : ______

Given below are groups of terms. The first pair indicates the relationship between the two terms. Complete the second pair accordingly.

Light reaction : Gran um : : Dark reaction : ______

Given below are groups of terms. The first pair indicates the relationship between the two terms. Complete the second pair accordingly.

Producers : Autotrophs : : Consumers : ______

Given below are groups of terms. The first pair indicates the relationship between the two terms. Complete the second pair accordingly.

Respiration: Carbon dioxide : : Photosynthesis : ______

Given below are groups of terms. The first pair indicates the relationship between the two terms. Complete the second pair accordingly.

Water and minerals : Xylem : : Prepared food : ______

Identify the false statement and rewrite it correctly by changing the first or last word only.

Dark reaction of photosynthesis occurs during night time.

Identify the false statement and rewrite it correctly by changing the first or last word only.

Photosynthesis requires enzymes.

Identify the false statement and rewrite it correctly by changing the first or last word only.

Green plants are consumers.

Identify the false statement and rewrite it correctly by changing the first or last word only.

Photosynthesis results in the loss of dry weight of the plants.

Identify the false statement and rewrite it correctly by changing the first or last word only.

Photosynthesis stops at a temperature of about 35°C.

Identify the false statement and rewrite it correctly by changing the first or last word only.

Photosynthesis occurs only in cells containing chloroplasts.

Identify the false statement and rewrite it correctly by changing the first or last word only.

Green plants perform photosynthesis.

Identify the false statements and rewrite them correctly by changing the first or last word only.

Algae are autotrophs.

The site of light reaction in the cells of a leaf is ______.

The chemical substance used to test the presence of starch in the cell of a leaf is ______.

Stroma is ground substance in ______.

The dark reaction of photosynthesis is known as ______.

In the flowering plants, food is transported in the form of ______.

Are the following statement true or false? Give a reason in support of your answer.

The rate of photosynthesis continues to rise as long as the intensity of light rises.

Are the following statement true or false? Give a reason in support of your answer.

The outside atmospheric temperature has no effect on the rate of photosynthesis.

Are the following statement true or false? Give a reason in support of your answer.

If you immerse a leaf intact on the plant in ice cold water, it will continue to photosynthesise in bright sunshine.

Are the following statement true or false? Give a reason in support of your answer.

Destarching of the leaves of a potted plant can occur only at night.

Are the following statement true or false? Give a reason in support of your answer.

If a plant is kept in bright light all the 24 hours for a few days, the dark reaction (biosynthetic phase) will fail to occur.

Are the following statement true or false? Give a reason in support of your answer.

Photosynthesis is considered as a process supporting all life on earth.

Given below are five terms. Rewrite the terms in the correct order so as to be in logical sequence with regard to photosynthesis:

(i) water molecules, (ii) oxygen, (iii) grana, (iv) hydrogen and hydroxyl ions, (v) photons.

State any four differences between photosynthesis and respiration.

Complete the following food chains by writing the names of appropriate organisms in the blanks:

Grass → ______ → Snake → ______

Complete the following food chains by writing the names of appropriate organisms in the blanks:

______ → Mouse ______ → Peacock

Name two aquatic plants which can be used for the experiment of photosynthesis.

Name two plants having variegated leaves.

Name two raw materials for photosynthesis.

Name four essentials for photosynthesis.

Name the two main phases of photosynthesis.

Match the terms given in column A with column B:

Complete the following by filling the blanks 1 to 5 with appropriate words/terms/phrases:

To test the leaf for starch, the leaf is boiled in water to ______ (1). It is next boiled in methylated spirit to ______ (2). The leaf is placed in warm water to soften it. It is then placed in a dish and ______ (3) solution is added. The region which contains starch, turns ______ (4) and the region which does not contain starch, turns ______ (5)

State the location:

Chlorophyll

Write the exact location of chloroplasts in the parts of a plant.

State the location:

Stroma

Write the exact location of guard cells.

Write the exact location of palisade cells.

Define Photosynthesis.

Define the following term:

Thylakoids

Define the following term:

Chloroplast

Define the following term:

Photolysis of water

Define the following term:

Polymerisation

Given below is the figure of an experimental set-up, showing a physiological act of the plants. Study and answer the following questions:

1. What is the objective of this experiment?
2. Name and define the process shown here.
3. Why do we destarch the leaves before performing the experiment?
4. How do we destarch the leaves?
5. What will be the observation when we pour iodine solution over the bleached experimental leaf?
6. Write a well-balanced equation for the above process.

Why is it necessary to place a plant in the dark before starting an experiment on photosynthesis? Explain.

Why is it not possible to demonstrate respiration in a green plant kept in sunlight?

Most leaves have the upper surface more green and shiny than the lower one. Why?

Give reasons/explain:

During the starch test, the leaf is boiled in water.

Give reasons/explain:

During the starch test, the leaf is boiled in methylated spirit.

Distinguish between the following pairs on the basis of the word indicated in the bracket ( ).

Light reaction and Dark reaction (end products)

Distinguish between the following pairs on the basis of the word indicated in the bracket ( ).

Producers and Consumers (organisms)

Mention one difference between the following on the basis of what is given in bracket.

Grass and grasshopper (mode of nutrition)

Distinguish between the following pairs on the basis of the word indicated in the bracket ( ).

Stoma and Stroma (structure)

Given below is a schematic diagram to illustrate some aspects of photosynthesis.

1. Fill up the gaps, in blank spaces (1-4), by writing the names of the correct items.
2. What phenomenon do the thick arrows A and B indicate?

Given below is the representation of a certain phenomenon in nature. With four organisms 1-4.

1. Name the phenomenon represented.
2. Name any one organism that could be shown at No. 5.
3. Name the biological process which was the starting point of the whole chain.
4. Name one natural element which all the organisms 2-4 and even 5 are getting from No. 1 for their survival.

A potted plant with variegated leaves was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours and then placed in bright sunlight for a few hours. Observe the diagrams and answer the questions:

1. What aspect of photosynthesis is being tested in the above diagram?
2. Represent the process of photosynthesis in the form of a balanced equation.
3. Why was the plant kept in the dark before beginning the experiment?
4. What will be the result of the starch test performed on Leaf ‘A’ shown in the diagram? Give an example of a plant with variegated leaves
5. Draw a neat labelled diagram of a chloroplast.

Given alongside is the diagram of an experimental set-up:

1. What is the objective of this experiment?
2. Will it work satisfactorily? Give reason.
3. What alteration(s) will you make in it for obtaining expected result?
4. Would you take any steps before starting the experiment? Describe this step and explain its necessity.

Draw a neat diagram of the stomatal apparatus found in the epidermis of leaves and label the Stoma, Guard cells, Chloroplast, Epidermal cells, Cell wall and Nucleus.

Given below is the diagram of an experimental set-up (final stage). Study the same and answer the following questions:

1. What is the main aim of the experiment?
2. Oxygen gas shown in the experiment is released from which of the raw materials?
3. How would you confirm the presence of oxygen gas?
4. Name the chemical substance which can be added in water to enhance the process/rate of release of oxygen gas.
5. Draw a neat and labelled diagram of the same experiment for its initial stage.

Given below are figures (A) and (B) showing open and closed stomatal apertures respectively.

Answer the questions that follow:

1. When do these stomata open (day/night)?
2. What is the condition of the guard cells when the stomata are open (turgid/flaccid)?
3. Name the gas taken in and released out through these pores during photosynthesis.
4. Name the cells of the lower epidermis that contain chloroplasts.
5. Write two characteristic features of both the inner and outer walls of the guard cells.