NCERT Solutions for Class 7 science Chapter 10: Life Processes in Plants Class 7

Chapter-wiseChapter 10 Life Processes in Animals Class 7 Questions and Answers are useful for focused study.

Class 7 Science Chapter 10 Life Processes in Animals Question Answer

Science Class 7 Chapter 10 Question Answer Life Processes in Animals

Life Processes in Animals Class 7 Question Answer (InText)

NCERT Class 7 Science Chapter 10 Question Answer Life Processes in Plants (Exercise)

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Answer:

(ii) What are the visible differences in plants in both the conditions?
Answer:
The plant kept in sunlight looks healthy and green as it performs photosynthesis while the plant kept in the dark room looks weak, pale, and yellowish because it cannot perform photosynthesis properly.

(iii) According to you, leaves of which plants confirm the iodine test for the presence of starch?
Answer:
The leaves of the plant kept in sunlight will confirm the iodine test for starch.

(ii) In which plant(s) in the above set-up(s) will starch not be formed?
Answer:
In all plants except the plant kept in sunlight with carbon dioxide.

(iii) In which plant(s) in the above set-up(s) will oxygen be generated?
Answer: Oxygen will be generated in a plant kept in sunlight with carbon dioxide.

(iv) In which plant(s) in the above set-up(s) will oxygen not be generated?
Answer:
Except for the plant kept in sunlight with carbon dioxide, oxygen will not be generated in any of the other plants.

Class 7 Life Processes in Animals Question Answer (Activities)

Activity 10.1: Let Us Test Some Explanations (Pages 138-139)Fig. Experimental set-up to understand the role of sunlight and water in plant growth(a) Pot A kept in direct sunlight, with water(b) Pot B kept in direct sunlight, without water(c) Pot C kept in dark with water

Table 10.1: Effects of sunlight and water on plant growth

Observation and Conclusion: The following points can be noted:
(i) What differences did you observe between the plants in the three pots?
Answer:
The plants in the three pots showed noticeable differences after two weeks.
Pot A, which received both sunlight and water, grew the tallest, had the most leaves, and stayed green, showing healthy development.
Pot B, with sunlight but no water, showed very little growth, fewer leaves, and yellowing due to dehydration.
Pot C, kept in the dark but watered, exhibited limited growth, with slightly pale yellow leaves and fewer new leaves, indicating that light is essential for healthy, green plants.

(ii) Which pot has the plant with the maximum growth?
Answer:
Pot A

(iii) Which pot has the plant with the least growth?
Answer:
Pot C

Activity 10.2: Let Us Check (Demonstration Activity) (Pages 140-141)

Fig. Starch test in a leaf, (a) Boiling set-up (b) Iodine test

Observation and Conclusion: If the colour of the leaf changes to blue-black, we can conclude that starch is present in the leaf.

Activity 10.3: Let Us Check (Pages 141-142)

Table 10.2: Presence of starch in green and non-green parts of the leaves of plants

Observation and Conclusion:
• Only the green parts of the leaf can perform photosynthesis and make starch due to the presence of chlorophyll.
• Sunlight is necessary for photosynthesis to occur and for starch to be produced in leaves.

Activity 10.4: Let us Experiment (Demonstration Activity) (Pages 143-144)

Fig. Testing the role of chlorophyll and air, (a) The set-up (b) Iodine test on the leaf

Observation and Conclusion:
• The part of the leaf that was inside the bottle with caustic soda (sodium hydroxide) did not turn blue-black after the iodine test. This shows that no starch was produced in that part because caustic soda absorbs carbon dioxide, which is needed for photosynthesis.

• The part of the leaf that was outside the bottle turned blue-black, showing that starch was produced because that part had access to carbon dioxide and could perform photosynthesis. This experiment proves that carbon dioxide is necessary for plants to prepare starch.

Activity 10.5: Let Us Explore (Page 145)

Fig. Activity showing the release of oxygen during photosynthesis

(i) What difference do you observe in the two set¬ups?
Answer:
In set-up A (kept in sunlight), we observe bubbles on the inverted test tube. While in set¬up B (kept in the dark), no bubbles are seen.

(ii) Do you observe air bubbles emerging in the inverted test tube in set-up A?
Answer:
Yes, air bubbles are seen rising and collecting in the inverted test tube in set-up A.

(iii) The gas produced in this set-up caused bubbles to emerge and get accumulated in the inverted test tube. Which gas is this?
Answer:
The gas produced is oxygen, which is released during photosynthesis.

Observation and Conclusion:
• When a test tube is taken off the set-up and a lit matchstick is inserted into the tube, it produces an intense flame, which confirms that oxygen gas is released during the process of photosynthesis.

Activity 10.6: Let Us Examine (demonstration activity) (Page 147)

Observation
(i) What do you observe?
Answer:
Tiny pores on the peel of the leaf.

(ii) Do you notice tiny pores on the peel?
Answer:
Yes

Conclusion:
• These tiny pores are stomata. They are prsent on the surface of leaves, help in the exchange of gases.

Fig. Stomata on the lower surface of a rhoeo leaf

Activity 10.7: Let Us Experiment (Page 148)

(a) With water (b) With coloured water plant twigs placed in water with different treatments

Fig. 10.7: Experiment to check for water transportation in plants

Observation and Conclusion:
• This experiment shows that water and minerals are transported through the xylem in plants. Xylem is thin, tube-like structure found in the stem, branches, and leaves, carrying water and minerals from the roots to all parts of the plant.

Activity 10.8: Let Us Find Out (Demonstration Activity) (Page 149)

Fig. Experiment to check for water transportation in plants
(a) With water
(b) With coloured water, plant twigs placed in water with different treatments
(c) With water
(d) With coloured water, plant twigs after one day
(e) Enlarged view of cut end of the twig

Observation and Conclusion:
• This experiment shows that water and minerals are transported through the xylem in plants. Xylem is thin, tube-like structure found in the stem, branches, and leaves, carrying water and minerals from the roots to all parts of the plant.

Activity 10.8: Let Us Find Out (Demonstration Activity) (Page 149)

Fig. Set-up to test respiration in plants

(i) Does the lime water turn milky in both the test tubes?
Answer:
The lime water turn milky only in the test tube connected to the flask.

(ii) Why does the lime water turn milky in the test tube connected to the flask?
Answer:
Lime water turns milky due to the presence of carbon dioxide. This carbon dioxide is produced by the seeds during respiration.

Observation and Conclusion:  Plants also respire like us and release carbon dioxide.