TRANSPORTATION IN ANIMALS AND PLANTS

 NOTES

Circulatory System

The organ system of the body that is responsible for the transport of material throughout the body is called the circulatory system.

Blood

• Blood is a fluid tissue that transports nutrients and oxygen to the cells and carries away carbon dioxide and other waste products in our body.

RBC

• Red blood cells (RBC) present in the blood are responsible for the transport of oxygen throughout the body.
• They contain a red pigment called haemoglobin, which binds with the oxygen.
• The reddish colour of the blood is due to haemoglobin.

WBC

• The blood contains white blood cells (WBC), which are part of the immune system.
• They are like soldiers, which fight and kill germs that may enter the body.

Blood Platelets

• Platelets are the smallest cells in the blood.
• By clumping together, they form a blood clot, preventing loss of blood due to bleeding.
• They prevent excessive damage to the blood vessels by binding together at the site of damage.

Excretion

The process of removal of waste products from the cells of living organisms is called excretion.

• For human beings, the waste products are in the form of carbon dioxide, urine and faeces.

Kidneys

• Our body’s main excretory organs are the kidneys.
• There is a pair of kidneys present on either side of the spine.
• Each kidney is a bean-shaped organ, reddish in colour.
• It contains millions of tiny tubules that act as microscopic filters and filter out the useful and harmful substances from the blood.
• The useful substances are again reabsorbed back into the blood and only harmful substances are concentrated.
• These harmful substances are present in a dissolved state in water and now it is called as urine.
• Urine is excreted out of the body.
• Thus, kidneys act as filters of our body.

Dialysis

• Dialysis is the filtering of blood outside the human body using a machine, when both the kidneys fail.

Phloem

• Phloem is the plant tissue that transports the soluble organic material created during photosynthesis from the leaves to the other parts of the plant.

Xylem

• Xylem is the plant tissue that transports the water and other nutrients from the roots to other parts of the plant.

QUESTION ANSWERS 

Exercise Questions

1. Match structures given in Column I with functions given in Column II.

Column- I	Column-II
(i) Stomata	(a) Absorption of water
(ii) Xylem	(b) Transpiration
(iii) Root hairs	(c) Transport of food
(iv) Phloem	(d) Transport of water
	(e) Synthesis of carbohydrates

Solution:

Column- I	Column-II
(i) Stomata	(b) Transpiration
(ii) Xylem	(d) Transport of water
(iii) Root hairs	(a) Absorption of water
(iv) Phloem	(c) Transport of food

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 .

Solution:

(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 salts .

(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 .

3. Choose the correct option:

(a) In plants, water is transported through

(i) xylem

(ii) phloem

(iii) stomata

(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

Solution:

a) i) Xylem

b) iii) under the fan

4. Why is transport of materials necessary in a plant or in an animal? Explain.

Solution:

Transport of materials is necessary in a plant or an animal for the following reasons:

• To transport food to various parts of the plant
• Animals need to transport wastes to parts from where they can be removed.

5. What will happen if there are no platelets in the blood?

Solution:

If there are no platelets, then blood will not clot as platelets release blood clotting factor at the site of injury and stops further bleeding.

6. What are stomata? Give two functions of stomata.

Solution:

Tiny pores present on the leaf surface are known as stomata.

Functions of stomata

• Helps in exchange of gases
• Evaporation of water through leaves occurs due to stomata.

7. Does transpiration serve any useful function in the plants? Explain.

Solution:

Transpiration serves the following functions in plants

• It helps in lowering temperature of plants, thus preventing heat injury of plants.
• Helps in transpiration pull, which helps in raining water in higher plants.
• It also causes loss of water absorbed by plants.

8. What are the components of blood?

Solution:

Red blood cells, white blood cells, platelets and plasma.

9. Why is blood needed by all the parts of a body?

Solution:

Blood is a significant part of transport system in our body, and we need blood for the following reasons:

• For the transport of oxygen to all parts of our body
• To expel out carbon dioxide from our body
• To transmit heat thus helping in the regulation of body temperature.
• It is required to fight out infections and diseases.

10. What makes the blood look red?

Solution:

Haemoglobin, a red pigment present in the blood makes it look red.

11. Describe the function of the heart.

Solution:

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 has four chambers. The two upper chambers are called the atria (singular: atrium), and the two lower chambers are called the ventricles. The partition between the chambers helps to avoid mixing up of blood-rich in oxygen with the blood-rich in carbon dioxide. Blood flows from the heart to the lungs and back to the heart from where it is pumped to the rest of the body.

12. Why is it necessary to excrete waste products?

Solution:

When our cells perform their functions, certain waste products are released. These are toxic and hence need to be removed from the body.

13. Draw a diagram of the human excretory system and label the various parts.

Solution: