NCERT Class VII: Science-Exercise Solutions
01-Nutrition in Plants
02-Nutrition in Animals
03-Fibre to Fabric
05-Acids Bases and Salts
06-Physical and Chemical Changes
07-Weather Climate and Adaptations of Animals to Climate
08-Winds Storms and Cyclones
10-Respiration in Organisms
11-Transportation in Animals and Plants
12-Reproduction in Plants
13-Motion and Time
14-Electric Current and its Effects
16-Water A Precious Resource
17-Forests Our Lifeline
Chapter 11-Transportation in Animals and Plants-Exercise Solutions
NCERT Book Exercise Page Number-131
Q.1. Match structures given in Column I with functions given in Column II.
Q.2. Fill in the blanks.
(i) The blood from the heart is transported to all parts of the body by the ___________.
(ii) Haemoglobin is present in ___________ cells.
(iii) Arteries and veins are joined by a network of ___________.
(iv) The rhythmic expansion and contraction of the heart is called ___________.
(v) The main excretory product in human beings is ___________.
(vi) Sweat contains water and ___________.
(vii) Kidneys eliminate the waste materials in the liquid form called ___________.
(viii) Water reaches great heights in the trees because of suction pull caused by ___________.
(i) The blood from the heart is transported to all parts of the body by the arteries.
(ii) Haemoglobin is present in red blood cells.
(iii) Arteries and veins are joined by a network of capillaries.
(iv) The rhythmic expansion and contraction of the heart is called heartbeat.
(v) The main excretory product in human beings is urea.
(vi) Sweat contains water and salt.
(vii) Kidneys eliminate the waste materials in the liquid form called urine.
(viii) Water reaches great heights in the trees because of suction pull caused by transpiration.
NCERT Book Exercise Page Number-132
Q.3. Choose the correct option:
(a) In plants, water is transported through
(iv) root hair
(b) Water absorption through roots can be increased by keeping the plants
(i) in the shade
(ii) in dim light
(iii) under the fan
(iv) covered with a polythene bag
(a) In plants, water is transported through (i) xylem.
(b) Water absorption through roots can be increased by keeping the plants (iii) under the fan.
Q.4. Why is transport of materials necessary in a plant or in an animal? Explain.
Answer: The cells of different organs of plants and animals need various necessary substances to carry out many metabolic activities and different type of waste products are created during these metabolic activities.
So, transport of materials is necessary to supply the required substances and to remove the waste products.
Q.5. What will happen if there are no platelets in the blood?
Answer: Platelets are responsible for clotting of blood. If there are no platelets, the blood would not clot in case of an injury. This will lead to excess blood loss and can even lead to death of a person.
Q.6. What are stomata? Give two functions of stomata.
Answer: The numerous pores under the surface of leaf are called stomata.
Functions of stomata-
(i) Transpiration(loss of water in the form of water vapours) and
(ii) exchange of gases (carbon dioxide and oxygen) are the main functions of stomata.
Q.7. Does transpiration serve any useful function in the plants? Explain.
Answer: Transpiration serves a very important function in plants. It is the loss of water through stomata. Transpiration creates the transpiration pull, which is responsible for the rise of water to great heights in tall plants and other trees.
Q.8. What are the components of blood?
Answer: Blood is a liquid, which has cells of various kinds suspended in it. Main components of blood are:
• Plasma: The fluid part of the blood is called plasma.
• RBC: One type of cells are the red blood cells (RBC) which contain a red pigment called haemoglobin.
• WBC: The blood also has white blood cells (WBC) which fight against germs that may enter our body.
• Platelets: The clotting of blood is caused by another type of cells in the blood, called platelets.
Q.9. Why is blood needed by all the parts of a body?
Answer: Blood transports substances like digested food from the small intestine to the other parts of the body. It carries oxygen from the lungs to the cells of the body. It also transports wastes for removal from the body.
So, it acts as a carrier of various substances. Every part of the body needs certain substances to perform their functions. Additionally, every part creates some waste products for removal.
Blood is needed by all parts of the body so that various substances can be supplied to them and waste can be removed from them.
Q.10. What makes the blood look red?
Answer: The presence of haemoglobin makes blood appear red. Haemoglobin has high affinity for oxygen and binds with it to form oxy-haemoglobin.
Q.11. Describe the function of the heart.
Answer: The heart is an organ which beats continuously to act as a pump for the transport of blood, which carries other substances with it.
The heart pumps the deoxygenated blood to the lungs for oxygenation and receives oxygenated blood from lungs. It pumps the oxygenated blood to different parts of the body. There is double circulation in a human heart that creates lub-dub sound.
Q.12. Why is it necessary to excrete waste products?
Answer: When our cells perform their functions, certain waste products are released. These are toxic for our body and hence need to be removed from the body. If they are not removed, they can cause certain problems to our body and can even cause some diseases.
Q.13. Draw a diagram of the human excretory system and label the various parts.