Textbook Solution: Transport of Substance in Living Beings | Class 7 Oxford Science: Chapter Notes, Worksheets & Tests PDF Download

A. Choose the correct option.

1.
Ans: (d)

2.
Ans: (a)

3.
Ans: (c)

4.
Ans: (d)

5.
Ans: (b)

B. Fill in the blanks with the correct words.

1.
Ans: The transport system in humans is made up of blood, blood vessels, and heart.

2. 
Ans: Wastes get removed from the cells and the body by a special process called excretion.

3. 
Ans: A fluid called blood flows inside pipelines called blood vessels.

4. 
Ans: The pulmonary artery carries blood from the heart to the lungs.

5. 
Ans: Kidneys are made up of tiny filtering units called nephrons.

6.  
Ans: Xylem carries water and minerals from the root to the stem and to the leaves.

C. Write T for true and F for false.

1.
Ans: The body undergoes various chemical reactions for its functioning during which waste materials are produced. - True

2.
Ans: Capillaries are the thinnest blood vessels and they connect arteries and veins. - False

3.
Ans: It is the heart that contracts and relaxes to pump blood, not the blood vessels. - False

4.
Ans: The left atrium opens into the left ventricle and the right atrium opens into the right ventricle, not the other way around. - False

5.
Ans: Through the process of transpiration, water is continuously lost from the leaves. - True

6.
Ans: Carbon dioxide is released as a result of respiration in plants and gets released through the stomata, not photosynthesis. - False

D. Answer the following questions.

1.
Ans: The different kinds of substances that need to be transported within a living body include nutrients absorbed by the small intestine, oxygen absorbed by the lungs, different minerals, and water. Waste products produced as a result of various chemical reactions also need to be transported out of the body.

2.
Ans: The three kinds of blood vessels found in humans are arteries, veins, and capillaries.

3.
Ans: Arteries and veins are two types of blood vessels that transport blood in the body. Arteries carry blood from the heart to different parts of the body and generally carry oxygenated blood. Veins, on the other hand, carry blood from different parts of the body back to the heart, and they generally carry deoxygenated blood.

4.
Ans: The circulatory system is a specialized organ system in multicellular organisms like humans, used for the purpose of transport. The main organs of the human circulatory system are the blood, blood vessels, and the heart.

5.
Ans: Blood is a red-colored fluid that flows within tubes called blood vessels. It carries various substances, such as nutrients, minerals, salts, respiratory gases, hormones, and even waste products to and from different parts of the body. It is made up of a straw-colored fluid called plasma, within which are suspended three different types of blood cells: red blood cells, white blood cells, and blood platelets.

6.
Ans: Pulse is the throbbing sensation felt at several places on the body, such as the wrist, neck, and inner arm, where the blood vessels come to the surface. It is a direct measure of the heartbeat.

7.
Ans: The four chambers of the heart are the left atrium, the right atrium, the left ventricle, and the right ventricle.

8.
Ans: Various things that need to be transported within a plant body include water for photosynthesis, different minerals required for proper growth and development, carbohydrates manufactured in the leaves during photosynthesis, and waste products that have accumulated within the plant body.

9.
Ans: Xylem and phloem are two types of tissues that make up the transport system in plants. Xylem carries water and minerals from the roots to the stem and leaves, while phloem carries carbohydrates manufactured in the leaves to all parts of the plant.

10.
Ans: Excretion is the process by which living organisms get rid of waste materials from their body. The main organs of the human excretory system are a pair of kidneys, a pair of ureters, a urinary bladder, and a urethra.

11.
Ans: The wastes that get created inside an animal body include carbon dioxide gas, sweat, and nitrogenous wastes, produced in the form of ammonia, urea, or uric acid.

12.
Ans: The human body gets rid of its wastes through exhalation of carbon dioxide from lungs, secretion of sweat from the skin, and removal of nitrogenous wastes in the form of urine through the excretory system.

13.
Ans: The three wastes excreted by plants are carbon dioxide, which is removed from the plant body through stomata, excess water which is also released from stomata through the process of transpiration, and many toxic wastes that get released from the plants in the form of secretions, such as gum, resins, and latex.