ANSWER: [B] Explanation: The given reaction is the reaction between Nitric Acid and Calcium Hydroxide to form Calcium Nitrate (a salt and water). The reaction between an acid and a base is known as “neutralization reaction”. It also involves formation of new compounds by the exchange of ions betweenRead more
ANSWER: [B]
Explanation: The given reaction is the reaction between Nitric Acid and Calcium Hydroxide to form Calcium Nitrate (a salt and water). The reaction between an acid and a base is known as “neutralization reaction”. It also involves formation of new compounds by the exchange of ions between reactants; it is also called “Double Displacement Reaction”.
ANSWER: [D] Explanation: Auxins are plant hormones that accumulate on the shaded side of the shoot when exposed to light. This higher concentration stimulates cells on the dark side to elongate more, causing the shoot to bend towards the light. This response is called phototropism. Cytokinins → promRead more
ANSWER: [D]
Explanation: Auxins are plant hormones that accumulate on the shaded side of the shoot when exposed to light. This higher concentration stimulates cells on the dark side to elongate more, causing the shoot to bend towards the light. This response is called phototropism.
Cytokinins → promote cell division.
Gibberellins → help in stem elongation and seed germination.
Adrenaline → an animal hormone, not a plant hormone.
Hence, the bending of shoots towards light is controlled by auxins.
ANSWER: (A) Explanation: Ozone depletion is mainly caused by chlorofluorocarbons (CFCs) from refrigerants, air-conditioners, and aerosols. CFCs release chlorine that destroys ozone molecules, thinning the protective layer. This allows harmful ultraviolet rays to reach Earth, causing skin cancer, catRead more
ANSWER: (A)
Explanation: Ozone depletion is mainly caused by chlorofluorocarbons (CFCs) from refrigerants, air-conditioners, and aerosols. CFCs release chlorine that destroys ozone molecules, thinning the protective layer. This allows harmful ultraviolet rays to reach Earth, causing skin cancer, cataracts, and crop damage. The ozone hole, seen prominently over Antarctica, highlights this issue. Ozone depletion differs from global warming, which concerns heat retention.
ANSWER: (C) Explanation: Parent cross: RRyy × rrYY Gametes: R y (from RRyy) and r Y (from rrYY) F₁ genotype: RrYy (all offspring same) Traits: R (round) is dominant over r (wrinkled). Y (yellow) is dominant over y (green). So, all F₁ seeds will show round and yellow phenotype. Thus, the plants of F₁Read more
ANSWER: (C)
Explanation:
Parent cross: RRyy × rrYY
Gametes: R y (from RRyy) and r Y (from rrYY)
F₁ genotype: RrYy (all offspring same)
Traits:
R (round) is dominant over r (wrinkled).
Y (yellow) is dominant over y (green).
So, all F₁ seeds will show round and yellow phenotype. Thus, the plants of F₁ generation will produce 100% round and yellow seeds.
ANSWER: (C) Explanation: Decomposers like bacteria and fungi break down dead plants, animals, and organic waste into simpler inorganic substances such as carbon dioxide, water, and minerals. These products are returned to the environment, where producers reuse them for photosynthesis and growth. ThuRead more
ANSWER: (C)
Explanation: Decomposers like bacteria and fungi break down dead plants, animals, and organic waste into simpler inorganic substances such as carbon dioxide, water, and minerals. These products are returned to the environment, where producers reuse them for photosynthesis and growth. Thus, decomposers recycle nutrients, clean the ecosystem of waste, and maintain the balance of nature.
The reaction 2HNO₃ + Ca(OH) ₂ → Ca(NO₃)₂ + 2H₂O is an example of:
ANSWER: [B] Explanation: The given reaction is the reaction between Nitric Acid and Calcium Hydroxide to form Calcium Nitrate (a salt and water). The reaction between an acid and a base is known as “neutralization reaction”. It also involves formation of new compounds by the exchange of ions betweenRead more
ANSWER: [B]
Explanation: The given reaction is the reaction between Nitric Acid and Calcium Hydroxide to form Calcium Nitrate (a salt and water). The reaction between an acid and a base is known as “neutralization reaction”. It also involves formation of new compounds by the exchange of ions between reactants; it is also called “Double Displacement Reaction”.
See lessThe plant hormone whose concentration stimulates the cells to grow longer on the side of the shoot which is away from light is:
ANSWER: [D] Explanation: Auxins are plant hormones that accumulate on the shaded side of the shoot when exposed to light. This higher concentration stimulates cells on the dark side to elongate more, causing the shoot to bend towards the light. This response is called phototropism. Cytokinins → promRead more
ANSWER: [D]
Explanation: Auxins are plant hormones that accumulate on the shaded side of the shoot when exposed to light. This higher concentration stimulates cells on the dark side to elongate more, causing the shoot to bend towards the light. This response is called phototropism.
Hence, the bending of shoots towards light is controlled by auxins.
See lessWhich are the correct statements regarding ozone depletion? (i) Chlorofluorocarbons (CFCs) are the main cause of ozone depletion. (ii) Ozone depletion increases harmful ultraviolet radiation reaching earth. (iii) Ozone hole is prominently observed over Antarctica. (iv) Ozone depletion protects humans from global warming.
ANSWER: (A) Explanation: Ozone depletion is mainly caused by chlorofluorocarbons (CFCs) from refrigerants, air-conditioners, and aerosols. CFCs release chlorine that destroys ozone molecules, thinning the protective layer. This allows harmful ultraviolet rays to reach Earth, causing skin cancer, catRead more
ANSWER: (A)
Explanation: Ozone depletion is mainly caused by chlorofluorocarbons (CFCs) from refrigerants, air-conditioners, and aerosols. CFCs release chlorine that destroys ozone molecules, thinning the protective layer. This allows harmful ultraviolet rays to reach Earth, causing skin cancer, cataracts, and crop damage. The ozone hole, seen prominently over Antarctica, highlights this issue. Ozone depletion differs from global warming, which concerns heat retention.
See lessIf pea plants with round and green seeds (RRyy) are crossed with pea plants having wrinkled and yellow seeds (rrYY), the seeds developed by the plants of F1 generation will be: (A) 50% round and green (B) 75% wrinkled and green (C) 100% round and yellow (D) 75% wrinkled and yellow
ANSWER: (C) Explanation: Parent cross: RRyy × rrYY Gametes: R y (from RRyy) and r Y (from rrYY) F₁ genotype: RrYy (all offspring same) Traits: R (round) is dominant over r (wrinkled). Y (yellow) is dominant over y (green). So, all F₁ seeds will show round and yellow phenotype. Thus, the plants of F₁Read more
ANSWER: (C)
Explanation:
Traits:
So, all F₁ seeds will show round and yellow phenotype. Thus, the plants of F₁ generation will produce 100% round and yellow seeds.
See lessThe decomposers in an ecosystem: (A) synthesise inorganic material from similar forms (B) synthesise organic compounds from simpler carbon compound (C) convert organic material into inorganic forms (D) convert inorganic materials into organic compounds
ANSWER: (C) Explanation: Decomposers like bacteria and fungi break down dead plants, animals, and organic waste into simpler inorganic substances such as carbon dioxide, water, and minerals. These products are returned to the environment, where producers reuse them for photosynthesis and growth. ThuRead more
ANSWER: (C)
Explanation: Decomposers like bacteria and fungi break down dead plants, animals, and organic waste into simpler inorganic substances such as carbon dioxide, water, and minerals. These products are returned to the environment, where producers reuse them for photosynthesis and growth. Thus, decomposers recycle nutrients, clean the ecosystem of waste, and maintain the balance of nature.
See less