ANSWER: [A] Explanation: The correct answer is A. Both A and R are true, and R is the correct explanation of A. The sex of a child is determined by the father’s chromosome. Father contributes either X or Y chromosome. XX → girl, XY → boy. Thus, the reason correctly explains the assertion.
ANSWER: [A]
Explanation: The correct answer is A. Both A and R are true, and R is the correct explanation of A.
The sex of a child is determined by the father’s chromosome.
Father contributes either X or Y chromosome.
XX → girl, XY → boy.
Thus, the reason correctly explains the assertion.
ANSWER: [D] Explanation: The correct answer is D. A is false but R is true. Assertion (A) is false → Maximum concentration of pesticides is found at the highest trophic level (top consumers), not the first level. Reason (R) is true → Pesticides are non-biodegradable and accumulate in organisms, causRead more
ANSWER: [D]
Explanation: The correct answer is D. A is false but R is true.
Assertion (A) is false → Maximum concentration of pesticides is found at the highest trophic level (top consumers), not the first level.
Reason (R) is true → Pesticides are non-biodegradable and accumulate in organisms, causing biomagnification.
Plants carry out both photosynthesis and respiration, but the amount of oxygen released during photosynthesis is far greater than the amount consumed during respiration. In photosynthesis, plants release large volumes of oxygen as a by-product while producing glucose. Although they use some oxygen fRead more
Plants carry out both photosynthesis and respiration, but the amount of oxygen released during photosynthesis is far greater than the amount consumed during respiration. In photosynthesis, plants release large volumes of oxygen as a by-product while producing glucose. Although they use some oxygen for their own energy needs during respiration, this is comparatively very small. Additionally, the vast number of plants on Earth constantly replenish the atmosphere with oxygen. Hence, the overall balance ensures no shortage of oxygen in the atmosphere.
ANSWER: Explain the multiple excretion way in plants. Gaseous waste: Oxygen released during photosynthesis and carbon dioxide during respiration diffuse out through stomata. Excess water: Removed by transpiration from stomata and lenticels. Storage of wastes: Resins and gums are deposited in dead xyRead more
ANSWER: Explain the multiple excretion way in plants.
Gaseous waste: Oxygen released during photosynthesis and carbon dioxide during respiration diffuse out through stomata.
Excess water: Removed by transpiration from stomata and lenticels.
Storage of wastes: Resins and gums are deposited in dead xylem.
Special products: Tannins, latex, and essential oils accumulate in leaves, bark, or fruits.
Leaf fall: In autumn, wastes are discarded along with shedding leaves.
Plants thus excrete by multiple simple ways without specialised organs.
In the process of respiration – (i) state the function of alveoli. (ii) state the function of stomata. (i) Alveoli in humans: Provide a very large surface area for gas exchange. Thin walls allow oxygen to diffuse into blood and carbon dioxide out. Rich network of capillaries ensures efficient transpRead more
In the process of respiration – (i) state the function of alveoli. (ii) state the function of stomata.
(i) Alveoli in humans: Provide a very large surface area for gas exchange. Thin walls allow oxygen to diffuse into blood and carbon dioxide out. Rich network of capillaries ensures efficient transport of gases.
(ii) Stomata in plants: Tiny pores on leaves regulate exchange of oxygen, carbon dioxide, and water vapor. Guard cells control opening and closing. Help plants balance respiration, photosynthesis, and water loss.
Q.8. Assertion (A): The sex of a child in human beings will be determined by the type of chromosome he/she inherits from the father. Reason (R): A child who inherits ‘X’ chromosome from his father would be a girl (XX), while a child who inherits a ‘Y’ chromosome from the father would be a boy (XY).
ANSWER: [A] Explanation: The correct answer is A. Both A and R are true, and R is the correct explanation of A. The sex of a child is determined by the father’s chromosome. Father contributes either X or Y chromosome. XX → girl, XY → boy. Thus, the reason correctly explains the assertion.
ANSWER: [A]
Explanation: The correct answer is A. Both A and R are true, and R is the correct explanation of A.
The sex of a child is determined by the father’s chromosome.
Father contributes either X or Y chromosome.
XX → girl, XY → boy.
See lessThus, the reason correctly explains the assertion.
Q.9. Assertion (A): The maximum concentration of chemicals and pesticides occurs at the first trophic level. Reason (R): The chemical and pesticides are not biodegradable.
ANSWER: [D] Explanation: The correct answer is D. A is false but R is true. Assertion (A) is false → Maximum concentration of pesticides is found at the highest trophic level (top consumers), not the first level. Reason (R) is true → Pesticides are non-biodegradable and accumulate in organisms, causRead more
ANSWER: [D]
Explanation: The correct answer is D. A is false but R is true.
Assertion (A) is false → Maximum concentration of pesticides is found at the highest trophic level (top consumers), not the first level.
Reason (R) is true → Pesticides are non-biodegradable and accumulate in organisms, causing biomagnification.
See lessPlants release oxygen during photosynthesis but also consume oxygen during respiration. Why does the atmosphere not face oxygen shortage because of this?
Plants carry out both photosynthesis and respiration, but the amount of oxygen released during photosynthesis is far greater than the amount consumed during respiration. In photosynthesis, plants release large volumes of oxygen as a by-product while producing glucose. Although they use some oxygen fRead more
Plants carry out both photosynthesis and respiration, but the amount of oxygen released during photosynthesis is far greater than the amount consumed during respiration. In photosynthesis, plants release large volumes of oxygen as a by-product while producing glucose. Although they use some oxygen for their own energy needs during respiration, this is comparatively very small. Additionally, the vast number of plants on Earth constantly replenish the atmosphere with oxygen. Hence, the overall balance ensures no shortage of oxygen in the atmosphere.
See lessExplain the multiple excretion way in plants.
ANSWER: Explain the multiple excretion way in plants. Gaseous waste: Oxygen released during photosynthesis and carbon dioxide during respiration diffuse out through stomata. Excess water: Removed by transpiration from stomata and lenticels. Storage of wastes: Resins and gums are deposited in dead xyRead more
ANSWER: Explain the multiple excretion way in plants.
- Gaseous waste: Oxygen released during photosynthesis and carbon dioxide during respiration diffuse out through stomata.
- Excess water: Removed by transpiration from stomata and lenticels.
- Storage of wastes: Resins and gums are deposited in dead xylem.
- Special products: Tannins, latex, and essential oils accumulate in leaves, bark, or fruits.
- Leaf fall: In autumn, wastes are discarded along with shedding leaves.
See lessPlants thus excrete by multiple simple ways without specialised organs.
In the process of respiration, – (i) state the function of alveoli. (ii) state the function of stomata.
In the process of respiration – (i) state the function of alveoli. (ii) state the function of stomata. (i) Alveoli in humans: Provide a very large surface area for gas exchange. Thin walls allow oxygen to diffuse into blood and carbon dioxide out. Rich network of capillaries ensures efficient transpRead more
In the process of respiration – (i) state the function of alveoli. (ii) state the function of stomata.
(i) Alveoli in humans: Provide a very large surface area for gas exchange. Thin walls allow oxygen to diffuse into blood and carbon dioxide out. Rich network of capillaries ensures efficient transport of gases.
(ii) Stomata in plants: Tiny pores on leaves regulate exchange of oxygen, carbon dioxide, and water vapor. Guard cells control opening and closing. Help plants balance respiration, photosynthesis, and water loss.
See less