CBSE Grade 7 Science - Nutrition, Fibers and Heat
Test your knowledge of 7th grade science topics including photosynthesis, nutrition in animals and plants, natural fibers like wool and silk, heat transfer, acids and bases, and the human circulatory system.
Questions
What is the colour of leaves in which chlorophyll is present?
- Green
- Red and purple
- Orange and yellow
- All of these
Why can't animals make food from carbon dioxide, water and minerals as plants do?
- Because animals move from one place to another.
- Because animals eat flesh and plants to live.
- Because animals don't have chloroplast like plants.
- Because animals cannot take in water and carbon dioxide.
Milk teeth fall at the age of ______and are replaced by.
- 4-6 years; molars
- 6 - 8 years; incisors
- 10 -14 years; permanent teeth
- 6 -8 years; permanent teeth
If along with the food some bacteria enter our body, who protects us from those bacteria?
- Mucus
- Hydrochloric acid
- Digestive juices
- Bile juice
Wool is obtained from ________.
- yak, sheep and rabbit
- goat, cat and camel
- sheep, horse and yak
- cat, sheep and goat
The __________fibres are made into wool for sweaters and the _____________fibres are spun into woollen cloth.
- shorter, silk
- longer, shorter
- dyed, natural
- straightened, curled
The difference in textures of silk yarn depends on ________.
- the silk moth from which it is obtained
- the protein secreted by the caterpillar
- the effect of sun and air on fibre secreted
- the method of weaving
In a clinical thermometer, what prevents mercury level from falling on its own?
- Kink inside the thermometer
- Good heat conducting nature of mercury
- Poor heat conducting nature of mercury
- Liquid state of mercury at room temperature
The land breeze flows from ___________to ____________at the _________time.
- sea, land, night
- land, sea, day
- land, sea, night
- sea, land, day
How do ruminants digest cellulose?
- With the help of bacteria in the large intestine.
- With the help of bacteria present in small intestine.
- With the help of bacteria in caecum.
- With the help of juices in stomach.
________coloured clothes absorb radiations better than _______________coloured clothes. That is why, we wear _______clothes in summers.
- Light, dark, dark
- Light, dark, light
- Dark, light, light
- Dark, light, dark
Which of the following is not an example of symbiotic relationship?
- Cuscutta and branches of another tree.
- Lichens in which alga and a fungus live together.
- Rhizobium bacteria and a leguminous plant.
- Honey bee and the flower.
The process of rechewing the ________to further break down the plant matter and stimulate digestion is called ________.
- complex matter; digestion
- cud; ruminating
- food; ingestion
- cud; digestion
Which of the following statements about Cuscutta plant is incorrect?
- It is a parasite.
- It is a heterotroph.
- It is a host plant.
- It is a yellow tubular climber.
Which of the following options is an incorrect pair of the organic acid and its source?
- Acetic acid - vinegar
- Formic acid - ant's sting
- Lactic acid - apple
- Ascorbic acid - amla
Why is goat's milk easier to digest than cow's milk?
- The fats in goat's milk are simpler.
- The goat's milk has a certain protein called alpha S1 casein.
- The goat's milk provide the more calcium than cow's milk.
- Goat's milk has highly evolved cholesterol than cow's milk
Which of the following opions is not an example of neutralisation?
- Taking antacid when stomach indigestion is there.
- Applying calamine solution when ant bites.
- Discharge of factory waste into water bodies.
- The soil treated by chemical fertilizers is treated with quick lime.
Which of the following options is not an adaptation of a polar bear to the severe conditions of polar regions?
- It has two thick layers of fur.
- It has long curved and sharp claws.
- It has a long tail.
- It has a thick layer of fat under its skin.
The blood vessel, which carries impure blood from heart to lungs is _____.
- pulmonary vein
- pulmonary artery
- capillary
- sinusoids
How does oxygen reach all parts of the body?
- It combines with the digested food.
- It gets attached to WBC (White Blood Cells).
- It gets attached to haemoglobin which is present in RBC (Red Blood Cells)
- It flows directly into vessels.
Why we sometimes see white patches on clothes in summers?
- Because salts are present in sweat.
- Because urea is present in sweat.
- Because the sweat has white colour.
- Because phosphorous and iron are present in sweat.
Why does the blood in the veins flow only towards heart and not backwards?
- Because veins have valves.
- Because the veins are divided into capillaries which are attached to heart.
- Because the carbon dioxide rich blood tends to flow towards the heart.
- Because the slope of veins is toward the heart.
Where are the buds present in a bryophyllum plant?
- On the root
- On the stem
- On the axil
- On the margin of its leaves
Haemoglobin is present in _____ and is _______ in colour.
- RBC, red
- WBC, red
- choloroplast, green
- chloroplast, red
The transport of water in plants takes place through _____.
- phloem
- stomata
- xylem
- roots