NCERT Class VII Science Solutions: Chapter 11-Transportation in Animals and Plants Part 4

Download PDF of This Page (Size: 176K)

Question 17:

Paheli noticed water being pulled up by a motor-pump to an overhead tank of a five-storeyed building. She wondered how water moves up to great heights in the tall trees standing next to the building. Can you tell why?

Answer:

When the water is pulled up by a motor – pump to an overhead tank of a five storeyed building, it moves to a great height due to the suction pull created by the pump. This pull forms a continuous column of water and water rises up to great height.

Similarly, when transpiration occurs in the leaves of a tall tree, water is evaporated through the pores called stomata. The continuous evaporation creates a suction force.

Due to this suction force, water from the soil rises up through the roots of the plants, and reaches to a great height in tall trees.

LONG ANSWER QUESTIONS

Question 18:

Match the parts of the heart in Column I with the direction of flow of blood in Column II.

Match the Column I and Column II (Q)
Match the Column I and Column II (Q)

Column I

Column II

Right ventricle

Pushes blood into the pulmonary artery.

Pulmonary veins

Take deoxygenated blood from the heart to lungs.

Left atrium

Receives blood from different parts of the body.

Pulmonary arteries

Bring oxygenated blood from lungs to the heart.

Left ventricle

Pushes blood into the aorta.

Right auricle

Receives deoxygenated blood from the pulmonary veins.

Answer:

Match the Column I and Column II (A)
Match the Column I and Column II (A)

Column I

Column II

Right ventricle

a. Pushes blood into the pulmonary artery.

Pulmonary veins

d. Bring oxygenated blood from lungs to the heart.

Left atrium

f. Receives deoxygenated blood from the pulmonary veins.

Pulmonary arteries

b. Take deoxygenated blood from the heart to lungs.

Left ventricle

e. Pushes blood into the aorta.

Right auricle

c. Receives blood from different parts of the body.

Question 19:

Read the following terms given below.

root hairs xylem urethra

arteries kidneys veins

atria capillaries heart

ureter phloem urinary bladder

Group the terms on the basis of the categories given below.

  1. Circulatory system of animals.

  2. Excretory system in human.

  3. Transport of substances in plants.

Answer:

  1. Arteries, atria, capillaries, veins, heart.

    Image of Circulatory system of animals

    Circulatory System of Animals

    Image of Circulatory system of animals

  2. Ureter, kidneys, urethra, urinary bladder.

    Image of Excretory system in human

    Excretory System in Human

    Image of Excretory system in human

  3. Root hairs, xylem, phloem.

Image of Transport of substance in plant

Transport of Substance in Plant

Image of Transport of substance in plant

Question 20:

Fill in the blanks of the following paragraph using just two words - arteries and veins.

__________carry oxygen-rich blood from the heart to all parts of the body and __________ carry carbon dioxide-rich blood from all parts of the body back to the heart.__________ have thin walls and __________ have thick elastic walls. Blood flows at high pressure in __________. Valves are present in __________ which allow blood to flow only towards the heart.__________ divide into smaller vessels. These vessels further divide into extremely thin tubes called capillaries. The capillaries join up to form __________.

Answer:

Arteries carry oxygen-rich blood from the heart to all parts of the body and veins carry carbon dioxide-rich blood from all parts of the body back to the heart. Veins have thin walls and arteries have thick elastic walls. Blood flows at high pressure in arteries. Valves are present in veins which allow blood to flow only towards the heart. Arteries divide into smaller vessels. These vessels further divide into extremely thin tubes called capillaries. The capillaries join up to form veins.

Question 21:

While learning to ride a bicycle Boojho lost his balance and fell. Ile got bruises on his knees and it started bleeding. However, the bleeding stopped after some time.

  1. Why did the bleeding stop?

  2. What would be the colour of the wounded area and why?

  3. Which type of blood cells are responsible for clotting of blood?

Answer:

  1. A blood clot had formed.

  2. Dark red due to clotting of blood.

  3. Platelets.