The following 20 Multiple Choice Questions (MCQ) are based on
Chapter 10: Life Processes in Plants from the NCERT Class 7
Science textbook Curiosity. Each question has four options - select the
best answer and click to check.
Instructions: Read each question carefully. Choose the most
appropriate option from (a), (b), (c), or (d). Click
Show Answer to reveal the correct answer with explanation.
Multiple Choice Questions
1Plants grow well when they receive suitable amounts of:
(a) Water, light, air and mineral nutrients
(b) Only soil without water
(c) Only darkness
(d) Food eaten through roots
(a) is correct
Growth depends on raw materials, energy and suitable environmental conditions.
2Leaves are called food factories because they carry out:
(a) Digestion
(b) Excretion only
(c) Seed dispersal
(d) Photosynthesis
(d) is correct
Leaves capture light and make carbohydrates from carbon dioxide and water.
3The green pigment that absorbs light energy is:
(a) Melanin
(b) Iodine
(c) Chlorophyll
(d) Haemoglobin
(c) is correct
Chlorophyll in chloroplasts captures energy for photosynthesis.
4Photosynthesis requires:
(a) Only minerals
(b) Carbon dioxide, water, sunlight and chlorophyll
(c) Oxygen and soil only
(d) Protein and fat
(b) is correct
These are the main raw materials and conditions for food production.
5The main carbohydrate formed during photosynthesis is represented as:
(a) Glucose
(b) Protein
(c) Fat only
(d) Mineral salt
(a) is correct
Plants form sugars that may be used, transported or stored as starch.
6The gas released during photosynthesis is:
(a) Nitrogen
(b) Carbon dioxide
(c) Hydrogen
(d) Oxygen
(d) is correct
Oxygen produced from water is released to the surroundings.
7The iodine test is used to detect:
(a) Fat
(b) Oxygen
(c) Starch
(d) Protein
(c) is correct
Iodine turns blue-black when starch is present.
8A leaf is first decolourised before the iodine test so that:
(a) Oxygen is removed forever
(b) The colour change can be seen clearly
(c) Starch is added
(d) Chlorophyll becomes starch
(b) is correct
Removing green pigment prevents it from masking the blue-black result.
9Plants take in carbon dioxide mainly through:
(a) Stomata
(b) Roots only
(c) Flowers only
(d) Xylem vessels
(a) is correct
Stomatal pores in leaves allow gas exchange.
10The opening and closing of stomata are controlled by:
(a) Root hairs
(b) Xylem
(c) Petals
(d) Guard cells
(d) is correct
Guard cells change shape to regulate the pore.
11Water and minerals enter a plant mainly through:
(a) Flowers
(b) Fruits
(c) Root hairs
(d) Stomata only
(c) is correct
Root hairs greatly increase contact with moist soil.
12The tissue that transports water and minerals upward is:
(a) Stomata
(b) Xylem
(c) Phloem
(d) Epidermis
(b) is correct
Xylem forms a conducting pathway from roots to stems and leaves.
13The tissue that transports prepared food is:
(a) Phloem
(b) Xylem
(c) Root hair
(d) Guard tissue
(a) is correct
Phloem distributes sugars from source leaves to other plant parts.
14Loss of water vapour from aerial plant parts is:
(a) Respiration
(b) Photosynthesis
(c) Germination
(d) Transpiration
(d) is correct
Water evaporates mainly through stomata.
15Transpiration helps pull water upward by creating:
(a) Carbon dioxide in roots
(b) New soil
(c) A suction effect in xylem
(d) Food in phloem
(c) is correct
Water loss from leaves helps maintain a continuous upward water column.
16Plants respire:
(a) Only while flowering
(b) Day and night
(c) Only during daytime
(d) Only at night
(b) is correct
Living plant cells continuously need energy.
17During respiration, plants generally use:
(a) Oxygen to release energy from food
(b) Carbon dioxide to make light
(c) Nitrogen to form water
(d) Only sunlight
(a) is correct
Aerobic respiration consumes oxygen and produces carbon dioxide and water.
18Photosynthesis and respiration differ because photosynthesis:
(a) Occurs in all cells without light
(b) Only releases energy from food
(c) Uses oxygen to make carbon dioxide
(d) Stores light energy in food
(d) is correct
Photosynthesis builds food, whereas respiration breaks food down to release energy.
19A plant kept without light cannot make starch normally because:
(a) Respiration requires darkness
(b) Chlorophyll disappears at once
(c) Photosynthesis requires light energy
(d) Roots stop absorbing every mineral instantly
(c) is correct
Light powers the reactions that manufacture carbohydrates.
20Mineral nutrients are important because plants use them to:
(a) Stop respiration
(b) Build tissues and support growth
(c) Replace all water
(d) Produce sunlight
(b) is correct
Elements such as nitrogen, phosphorus and potassium are needed for vital plant compounds and functions.
