ANSWER: (C) Explanation: Assertion (A): The amount of ozone in the atmosphere began to drop sharply in the 1980s. Reason (R): The oxygen atoms combine with molecular oxygen to form ozone. The assertion is true, as ozone depletion was first observed prominently in the 1980s. The reason is false, becaRead more
ANSWER: (C)
Explanation: Assertion (A): The amount of ozone in the atmosphere began to drop sharply in the 1980s.
Reason (R): The oxygen atoms combine with molecular oxygen to form ozone.
The assertion is true, as ozone depletion was first observed prominently in the 1980s.
The reason is false, because the drop was due to CFCs breaking ozone, not due to oxygen forming ozone.
ANSWER: Yes, plants also require carbohydrates, proteins, and fats, but they prepare them on their own. Through photosynthesis, plants make glucose (a carbohydrate), which provides energy and acts as the basic raw material. Proteins are formed when plants absorb nitrates from soil, which combine witRead more
ANSWER: Yes, plants also require carbohydrates, proteins, and fats, but they prepare them on their own. Through photosynthesis, plants make glucose (a carbohydrate), which provides energy and acts as the basic raw material. Proteins are formed when plants absorb nitrates from soil, which combine with glucose to produce amino acids and then proteins. Fats are produced when glycerol and fatty acids are synthesised inside plant cells using carbohydrates. Unlike humans, plants are autotrophs, so they manufacture these nutrients internally rather than consuming them.
ANSWER: The transport system in plants is relatively slower than in animals because plants do not have a pumping organ like the heart. Instead, they rely on processes such as diffusion, osmosis, and transpiration pull, which are passive and slower in comparison. Moreover, plants do not require rapidRead more
ANSWER: The transport system in plants is relatively slower than in animals because plants do not have a pumping organ like the heart. Instead, they rely on processes such as diffusion, osmosis, and transpiration pull, which are passive and slower in comparison. Moreover, plants do not require rapid transport since they are sedentary and their needs for oxygen and food are lower.
Phloem plays an important role in translocation. It transports prepared food, mainly sucrose, from the leaves (source) to storage organs, stems, roots, fruits, and growing regions (sink) through the process of active transport.
Phloem plays an important role in translocation. It transports prepared food, mainly sucrose, from the leaves (source) to storage organs, stems, roots, fruits, and growing regions (sink) through the process of active transport.
ANSWER: Besides minimising the loss of blood, plugging any leak in a blood vessel is essential to prevent germs and pathogens from entering the body, which could cause infections and diseases. The component of blood responsible for this process is platelets. When a blood vessel is cut, platelets gatRead more
ANSWER: Besides minimising the loss of blood, plugging any leak in a blood vessel is essential to prevent germs and pathogens from entering the body, which could cause infections and diseases. The component of blood responsible for this process is platelets. When a blood vessel is cut, platelets gather at the site of injury, release clotting factors, and help in the formation of fibrin threads. These threads trap blood cells, forming a clot that seals the wound. This prevents excessive bleeding and entry of harmful microorganisms into the bloodstream.
Assertion (A): The amount of ozone in the atmosphere began to drop sharply in the 1980s. Reason (R): The oxygen atoms combine with molecular oxygen to form ozone.
ANSWER: (C) Explanation: Assertion (A): The amount of ozone in the atmosphere began to drop sharply in the 1980s. Reason (R): The oxygen atoms combine with molecular oxygen to form ozone. The assertion is true, as ozone depletion was first observed prominently in the 1980s. The reason is false, becaRead more
ANSWER: (C)
Explanation: Assertion (A): The amount of ozone in the atmosphere began to drop sharply in the 1980s.
Reason (R): The oxygen atoms combine with molecular oxygen to form ozone.
- The assertion is true, as ozone depletion was first observed prominently in the 1980s.
- The reason is false, because the drop was due to CFCs breaking ozone, not due to oxygen forming ozone.
See lessJust as humans require carbohydrates, proteins and fats, do plants require carbohydrates, proteins and fats in the same way? Explain.
ANSWER: Yes, plants also require carbohydrates, proteins, and fats, but they prepare them on their own. Through photosynthesis, plants make glucose (a carbohydrate), which provides energy and acts as the basic raw material. Proteins are formed when plants absorb nitrates from soil, which combine witRead more
ANSWER: Yes, plants also require carbohydrates, proteins, and fats, but they prepare them on their own. Through photosynthesis, plants make glucose (a carbohydrate), which provides energy and acts as the basic raw material. Proteins are formed when plants absorb nitrates from soil, which combine with glucose to produce amino acids and then proteins. Fats are produced when glycerol and fatty acids are synthesised inside plant cells using carbohydrates. Unlike humans, plants are autotrophs, so they manufacture these nutrients internally rather than consuming them.
See lessThe transport system in plants is relatively slower than in animals. Give reasons.
ANSWER: The transport system in plants is relatively slower than in animals because plants do not have a pumping organ like the heart. Instead, they rely on processes such as diffusion, osmosis, and transpiration pull, which are passive and slower in comparison. Moreover, plants do not require rapidRead more
ANSWER: The transport system in plants is relatively slower than in animals because plants do not have a pumping organ like the heart. Instead, they rely on processes such as diffusion, osmosis, and transpiration pull, which are passive and slower in comparison. Moreover, plants do not require rapid transport since they are sedentary and their needs for oxygen and food are lower.
See lessState the role of phloem in the transport of materials in plants.
Phloem plays an important role in translocation. It transports prepared food, mainly sucrose, from the leaves (source) to storage organs, stems, roots, fruits, and growing regions (sink) through the process of active transport.
Phloem plays an important role in translocation. It transports prepared food, mainly sucrose, from the leaves (source) to storage organs, stems, roots, fruits, and growing regions (sink) through the process of active transport.
See lessBesides minimising the loss of blood, why is it essential to plug any leak in a blood vessel? Name the component of blood which helps in this process and state how this component performs this function.
ANSWER: Besides minimising the loss of blood, plugging any leak in a blood vessel is essential to prevent germs and pathogens from entering the body, which could cause infections and diseases. The component of blood responsible for this process is platelets. When a blood vessel is cut, platelets gatRead more
ANSWER: Besides minimising the loss of blood, plugging any leak in a blood vessel is essential to prevent germs and pathogens from entering the body, which could cause infections and diseases. The component of blood responsible for this process is platelets. When a blood vessel is cut, platelets gather at the site of injury, release clotting factors, and help in the formation of fibrin threads. These threads trap blood cells, forming a clot that seals the wound. This prevents excessive bleeding and entry of harmful microorganisms into the bloodstream.
See less