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प्रश्न
Why is diffusion insufficient to meet the oxygen requirements of large multicellular organisms like humans?
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उत्तर
In small unicellular animals, such as Amoeba, the volume of their body is so small that oxygen can be introduced quickly into the whole body by the process of diffusion. This is because the cell of Amoeba is so small that the oxygen does not have to go far. But in case of large multicellular animals like humans, the volume of the body is so big that oxygen cannot quickly diffuse into all the cells of the body. This is because in these cases, the oxygen has to travel a very large distance to reach each and every cell of the body.
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संबंधित प्रश्न
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
What would be the consequences of a deficiency of haemoglobin in our bodies?
Given below is a square of letters in which are hidden different words related to respiration in organisms. These words may be present in any direction − upwards, downwards, or along the diagonals. Find the words for your respiratory system. Clues about those words are given below the square.
- The air tubes of insects
- Skeletal structures surrounding chest cavity
- Muscular floor of chest cavity
- Tiny pores on the surface of leaf
- Small openings on the sides of the body of an insect
- The respiratory organs of human beings
- The openings through which we inhale
- An anaerobic organism
- An organism with tracheal system
Name the pores in a leaf through which respiratory exchange of gases takes place.
Define breathing. State the differences between breathing and respiration.
Give the main points of difference between respiration in plants and respiration in animals.
Which of the following statements are true about respiration?
(i) during inhalation, ribs move inward and diaphragm is raised.
(ii) the gaseous exchange takes place in the alveoli.
(iii) haemoglobin has greater affinity for carbon dioxide than oxygen.
(iv) alveoli increase surface area of the exchange of gases
The breathing and respiration in woody stem of a plant takes place through:
A, B and C are three living organisms. The organism A is a unicellullar fungus which can live without air. It is used in the commercial production of an organic compound P from molasses. The organism B is a unicellular animal which lives in water and feeds and moves by using pseudopodia. It breathes through an organelle Q. The organism C is a tiny animal which acts as a carrier of malarial parasite. It breathes and respires through a kind of tiny holes R and air-tubes S in its body.
(a) What are organisms (i) A (ii) B, and (iii) C?
(b) Name (i) P (ii) Q (iii) R, and (iv) S.
(c) Which organism/organisms undergo aerobic respiration?
(d) Which organism/organisms undergo anaerobic respiration?
Some sugar solution is taken in a test-tube and a little of substance X in powder form is added to it. The mouth of test-tube is closed with a cork and allowed to stand for sometime. On opening the cork, a characteristic smell of substance Y is obtained and a gas Z is also observed to be formed. The gas Z extinguishes a burning matchstick.
(a) What could be (i) X, (ii) Y, and (iii) Z?
(b) What is the process of converting sugar into substance Y by the action of X known as?
(c) What type of respiration is exhibited by X in the above process?
It has been found that people living in very high mountains have many more red corpuscles in their blood than people living in plains. Which one of the following best accounts for this phenomenon?
In the lungs what substance is removed from the body?
Given below is an example of a certain structure and its special functional activity:
"Kidney and excretion".
Fill in the blanks on a similar pattern.
Pleura and _____________.
Complete the analogy.
Transport of CO2 by plasma : 7% :: Transport of CO2 by bicarbonate ions: ____________.
______ refers to the physical process by which gaseous exchange takes place between the atmosphere and the lungs.
Which is the correct sequence of air passage during inhalation?
Explain the three pathways of breakdown in living organisms.
On a very cold morning, Boojho and Paheli were talking with each other as they walked down to their school. They observed that the air coming out of their mouth looked like smoke. They were amused and wondered how it happened. Help them find the answer.
Match the correct answers with the type of respiration and respiratory substances.
| Respiration | Types of Substrates |
| A. Floating respiration | I. Proteins |
| B. Cytoplasmic respiration | II. Glucose |
| C. Protoplasmic respiration | III. Carbohydrates and fats |
