Life Processes in Animals — Quiz

Q1. In Activity 9.1, Priya adds iodine to boiled rice in test tube A and chewed boiled rice in tube B. The colour in tube A turns blue-black. This indicates the presence of

• A. Starch
• B. Sugar
• C. Protein
• D. Fat

Q2. Ravi swallows a bite of chapati. Even when he stands on his head, the food still reaches his stomach. The most appropriate reason is that

• A. Gravity pulls the food down strongly
• B. Saliva makes the food slip down easily
• C. Wave-like contractions of the food-pipe walls push food forward
• D. The stomach sucks the food up by suction

Q3. The stomach lining produces mucus along with the digestive juice and acid. The main role of this mucus is to

• A. Help digest proteins
• B. Kill harmful bacteria in food
• C. Protect the stomach lining from the acid
• D. Absorb digested nutrients into the blood

Q4. A Class 7 student asks why bile is important even though it does not contain a digestive enzyme. The best explanation is that bile

• A. Breaks proteins into amino acids
• B. Breaks fat into tiny droplets so that it can be digested more easily
• C. Absorbs water from undigested food
• D. Stores nutrients for later use

Q5. Pancreatic juice, secreted by the pancreas into the small intestine, helps to break down

• A. Only carbohydrates
• B. Only proteins
• C. Only fats
• D. Carbohydrates, proteins and fats

Q6. After most of the nutrients are absorbed in the small intestine, the remaining undigested food enters the large intestine. The main function of the large intestine is to

• A. Absorb water and some salts, making the waste semi-solid
• B. Digest proteins and fats with strong juices
• C. Produce bile to break down fats
• D. Exchange gases between blood and food

Q7. A doctor advises Priya's grandmother to eat more fruits, vegetables and whole grains. Fibre-rich foods help the large intestine to function properly mainly by

• A. Killing harmful bacteria
• B. Producing more bile
• C. Making the stool easier to pass
• D. Increasing absorption of fat

Q8. A cow spends about how many hours a day in just chewing its food?

• A. 2 hours
• B. 4 hours
• C. 6 hours
• D. 8 hours

Q9. Health teachers in a Rampur school advise students to breathe through the nose and not through the mouth. The best science reason is that

• A. Air entering through the nose is warmer than air through the mouth
• B. Tiny hair and mucus in the nasal passage trap dust and dirt from the air
• C. The mouth has bacteria that infect the lungs
• D. Air through the nose contains more oxygen than through the mouth

Q10. During inhalation, which of the following changes correctly takes place in the human chest?

• A. Ribs move up and outwards; diaphragm moves downward
• B. Ribs move down and inwards; diaphragm moves upward
• C. Ribs do not move; diaphragm moves downward
• D. Ribs move up and outwards; diaphragm moves upward

Q11. In Activity 9.2, Manish makes a model with a plastic bottle, a Y-tube, two balloons and a rubber sheet across the open base. When he pulls the rubber sheet downwards, the balloons

• A. Burst with a sound
• B. Inflate (become bigger)
• C. Deflate (become smaller)
• D. Do not change in size

Q12. In Activity 9.3, students take freshly prepared lime water in test tubes A and B. Tube A receives surrounding air via a syringe; tube B receives air exhaled through a straw. Lime water in tube B turns milky because exhaled air contains more

• A. Nitrogen
• B. Oxygen
• C. Carbon dioxide
• D. Water vapour

Q13. According to Fig. 9.13, the percentages of oxygen in inhaled air and exhaled air are approximately

• A. 21% and 16–17%
• B. 16–17% and 21%
• C. 78% and 4–5%
• D. 4–5% and 21%

Q14. Which of the following is the correct word equation for the process of respiration as given in the chapter?

• A. Glucose + Oxygen → Carbon dioxide + Water + Energy
• B. Carbon dioxide + Water → Glucose + Oxygen
• C. Glucose + Carbon dioxide → Oxygen + Water
• D. Oxygen + Water → Glucose + Energy

Q15. Frogs live both on land and in water. An adult frog mainly uses which combination for breathing?

• A. Only gills, both on land and in water
• B. Lungs on land; lungs and skin while in water
• C. Only skin, both on land and in water
• D. Lungs on land; gills in water