CBSE Class 7
2023-24
Time: 3 hours Subject: Science Total Marks: 50
General Instructions:
1. This question paper consists of 39 questions in 5 sections.
2. All questions are compulsory. However, internal choice is provided.
3. Section A comprises of 20 objective type questions carrying 1 mark
each.
4. Section B comprises of 6 very short answer type questions carrying 2
marks each.
5. Section C comprises of 4 short answer type question carrying 3 marks
each.
6. Section D comprises of Case Based questions carrying 3 mark each.
SECTION A
Q1. Fill in blanks.
1. The green pigment of the leaves called ________.
2. The ……………… help in the opening and closing of the stomata.
3. Plants can synthesise components of food other than carbohydrates
such as ……………… and ……………….
4. ……………… feed on dead and decaying matters.
5. ……………… derives nutrients from other organisms without
benefiting them.
Q2. Match the following.
Column A Column B
1. Mango tree (a) Insectivorous plant
2. Mushroom (b) Heterotroph
3. Pitcher Plant (c) Autotroph
4. Cuscuta (d) Saprophyte
5. Elephant (e) Parasitic
Q3. True or False.
1. Oxygen is not released during photosynthesis.
2. Yeast and mushrooms are useful for us.
3. The cell is enclosed by a thin outer boundary called cytoplasm.
4. Crop require a lot of carbohydrate to make protein.
5. Lichens are an example of a parasite.
Q4. Multiple choice questions.
1. Organisms which prepare food for themselves using simple, naturally
available raw materials are referred to as
(a) heterotrophs (c) parasites
(b) autotrophs (d) saprophytes
2. In the absence of which of the following, will photosynthesis not occur in
leaves?
(a) Guard cells (c) Vacuole
(b) Chlorophyll (d) Space between cells
3. Pitcher plant traps insects because it
(a) is a heterotroph. (c) does not have chlorophyll.
(b) grows in soils which lack (d) has a digestive system like
nitrogen. human beings.
4. When we observe the lower surface of a leaf through a magnifying lens, we
see numerous small openings. Which of the following is the term given to
such openings?
(a) Stomata (c) Midrib
(b) Lamina (d) Veins
5. Two organisms are good friends and live together. One provides shelter,
water, and nutrients, while the other prepares and provides food. Such an
association of organisms is termed as
(a) saprophyte (c) autotroph
(b) parasite (d) symbiosis
SECTION B
Q5. Very short answer type questions. [30-40 words]
1. Wheat dough is left in the open, and after a few days, it starts to emit a
foul smell and becomes unfit for use. Give reason.
OR
Algae are green in colour. Justify the statement.
2. Why does green patches form in pond’s water? Why algae are green in
colour?
3. Potato and ginger are both underground parts that store food. Where is
the food prepared in these plants?
4. Nitrogen is an essential nutrient for plant growth. But farmers who
cultivate pulse crops like green gram, Bengal gram, black gram, etc., do
not apply nitrogenous fertilizers during cultivation. Why?
5. What is Symbiosis? Give one example.
OR
What are parasites.
6. What are cells? What is cytoplasm?
SECTION C
Q6. Short answer type questions. [50-60 words]
1. What is Stomata? What is the function of chlorophyll? Which
substances are used during photosynthesis? Which gas is released
during photosynthesis?
OR
Wild animals like tiger, wolf, lion and leopard do not eat plants. Does
this mean that they can survive without plants? Can you provide a
suitable explanation?
2. Draw a neat and labelled diagram of Stomata and label the following
terms given in the box. Stomatal opening, guard cell
3. Autotrophs and heterotrophs are two different organisms with distinct
modes of nutrition state. How are they different from each other?
4. Nitrogen is an essential nutrient for plant growth. But farmers who
cultivate pulse crops like green gram, Bengal gram, black gram, etc., do
not apply nitrogenous fertilisers during cultivation. Why?
SECTION D
Q8. Case based questions.
i.
Plants synthesise carbohydrates through the process of
photosynthesis. The carbohydrates are made of carbon, hydrogen and
oxygen. These are used to synthesise other components of food such as
proteins and fats. But proteins are nitrogenous substances which
contain nitrogen. Nitrogen is present in abundance in gaseous form in
the air.
However, plants cannot absorb nitrogen in this form. Soil has certain
bacteria that convert gaseous nitrogen into a usable form and
release it into the soil. These are absorbed by the plants along with
water. Also, you might have seen farmers adding fertilisers rich in
nitrogen to the soil. In this way the plants fulfil their requirements of
nitrogen along with the other constituents. Plants can then
synthesise proteins and vitamins.
Besides leaves, photosynthesis also takes place in other green parts
of the
Plant — in green stems and green branches. The desert plants have
scale- or spine-like leaves to reduce loss of water by transpiration.
These plants have green stems which carry out photosynthesis.
1. Carbohydrates are made up of which of the following components?
(a) Hydrogen (c) Oxygen
(b) Carbon (d) All of the above
2. _______________is a nitrogen containing compound?
(a) Carbohydrates (c) Oxygen
(b) Hydrogen (d) Proteins
3. How does desert plants reduce loss of water by transpiration?
4. How do plants fulfil their requirements of nitrogen?
ii.
Oxygen which is essential for the survival of all organisms is produced
during photosynthesis. In the absence of photosynthesis, life would be
impossible on the earth. During photosynthesis, chlorophyll containing
cells of leaves, in the presence of sunlight, use carbon dioxide and
water to synthesise carbohydrates. The process can be represented in
an equation: During the process oxygen is released. The presence of
starch in leaves indicates the occurrence of photosynthesis. Starch is
also a carbohydrate
Carbon dioxide+ water ——– sunlight——–> carbohydrate+ oxygen
1. Which of the following organism produces oxygen?
(a) Humans (c) Bacteria
(b) Plants (d) Fungi
2. Photosynthesis occurs in the presence of light?
(a) True (c) Both (a)&(b)
(b) False (d) None of the above
3. Write the equation of photosynthesis?
4. What is the indication of the occurrence of photosynthesis in a plant?
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