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Class seven science Chap 10 Very short answers
Chapter 10: Respiration in Organisms
Additional Questions
Objective Questions
A. Write whether the following statements are True/False:
1. Yeasts are multicellular organisms.
2. Hot water bath or massage improves the circulation of blood.
3. While eating, sleeping or reading we don’t require energy.
4. A cell is the smallest structural and functional unit of an organism.
5. During breathing, inhalation and exhalation take place alternately.
6. On average, the breathing rate of an adult human is 60 times in a minute.
Answers
1. False
2. True
3. False
4. True
5. True
6. False
B. Match the following:
Answers
1. B
2. A
3. D
4. C
C. Fill in the blanks:
1. The process of breakdown of food in the cell with the release of energy is called
______________.
2. Yeasts are ________celled organisms.
3. The cramps occur when muscle cells respire____________.
4. The partial breakdown of glucose produces ______________.
5. When we inhale air, it passes through our _________ into the nasal cavity.
6. Lungs are present in the ________ cavity.
Answers
1. cellular respiration
2. single
3. anaerobically
4. lactic acid
5. nostrils
6. chest
Very short Questions
1. What is a cell?
Answers A cell is the smallest structural and functional unit of an organism.
2. Define cellular respiration?
Answers The process of breakdown of food in the cell with the release of energy is called cellular respiration.
3. Name the organs which are used for gaseous exchange in fish?
Answers Fish have gills for gaseous exchange.
4. Name some animals that have the respiratory organs and the process of breathing similar to those of humans?
Answers Cow, buffalo, dog and cat are some of the animals that have the respiratory organs and the process of breathing similar to those
of humans.
5. What is the normal range of breathing rate in an average adult person at rest?
Answers The normal range of breathing rate in an average adult person at rest is 15–18 times a minute.
6. What is inhalation?
Answers The taking in of air rich in oxygen into the body during breathing is called inhalation.
7. What is exhalation?
Answers Giving out of air rich in carbon dioxide from the body is known as exhalation.
8. How much air can be holed by the lungs of an average adult?
Answers 5–6 litres air can be holed by the lungs of an average adult.
Short Questions
1. Whenever we feel drowsy or sleepy, we start yawning. Does yawning help us in any way?
Answers When we are sleepy or feel drowsy, we yawn because our brain cells lack a sufficient amount of oxygen. The deep breath associated with yawning helps in drowning more oxygen and supply the needed amount of oxygen to the tired body organs including the brain.
2. How the process of exhalation does take place in our body?
Answers During exhalation, the ribs move down and inwards, while diaphragm moves up to its original position. This decreases the size of the chest cavity and the air is pushed out of the lungs.
3. Why do we need to eat food regularly?
Answers The food we eat gets converted into glucose which further gets converted into energy through respiration.
4. Why oxygen is needed for the people going to high altitude?
Answers People going to high altitude used to carry oxygen with them because the amount of air available to a person is less than that on
the ground.
5. What would happen if a potted plant is overwatered?
Answers If the potted plant is overwatered, the air-filled between the soil particles would be replaced by excess water and roots of the plants would not able to breathe inside the soil that causes the decay of roots and then the death of the plant.
6. Arrange the given activities in the increasing order of breathing rate and also explain the reason for your arranged order. sleeping, running, brisk walk and playing a video game.
Answers Do it yourself.
Long Questions
1. How does the respiration in cockroaches take place?
Answers A cockroach has small openings on the sides of its body. These openings are called spiracles. They have tracheae, a network of air tubes used for gas exchange. Oxygen wealthy air rushes through spiracles into the tracheal tubes, diffuses into the body tissue and reaches in every cell of the body. In a similar way, carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles.
2. While kneading dough for making a cake, your mother added a mixture of yeast and sugar to the dough and kept half of that
kneaded dough in a warm place for a few hours. The half of the dough, kept in a warm place, was double from its earlier size and also smelling sour. What is the reason for its sour smell and its double size? Why did she add sugar with yeast only for adding taste in the dough? Did she keep rest of the dough in the refrigerator instead of keeping in a warm
place, why?
Answers Yeast is known as anaerobe because it produces energy through anaerobic respiration.
Alcohol gave the dough a sour smell and the dough rose double in size because of the release of carbon dioxide. She added sugar with yeast because yeast feeds on sugar and glucose is produced. Yeast needs a warm place to grow and multiply and almost inactive in low temperature. Therefore, she kept the dough in the refrigerator, so that the reaction cannot take place and yeast cannot grow and multiply.
The dough would remain the same in the size and can be preserved for sometimes.
3. Observe the given image carefully and answer the following questions:
a. Which process is being tested in the given activity?
b. W hat is the result of the activity?
Answers
a. The presence of carbon dioxide in the exhaled air is being tasted in the given activity.
b. When the exhaled air is passed through lime water, due to the presence of carbon dioxide in exhaled air, it turns into milky. The turning of lime water into milky is a standard taste of carbon dioxide.