Explanation

• The ozone layer in the stratosphere absorbs most of the Sun’s harmful ultraviolet (UV) radiation.
• It particularly absorbs UV-B and UV-C rays, protecting living organisms from harmful effects.

Last verified on 01-11-2026

Explanation

• Photochemical smog forms when nitrogen oxides (NOₓ) and volatile organic compounds (VOCs) react in sunlight.
• Its characteristic components include ground-level ozone (O₃) and peroxyacetyl nitrate (PAN).
• Other pollutants, such as nitrogen dioxide and aldehydes, may also be present.

Last verified on 01-11-2026

Explanation

• Genetically engineered bacteria, particularly E. coli.
• They are used to produce human insulin commercially.
• The human insulin gene is introduced into bacteria using recombinant DNA technology.
• The bacteria produce insulin, which is purified and used to treat diabetes.

Last verified on 01-11-2026

Explanation

• Species interact within a community through feeding, shelter requirements, and their habits.
• These interactions include competition, predation, mutualism, and parasitism.
• Such relationships develop over time through interactions between organisms and their environment.

Last verified on 01-11-2026

Explanation

• An ecological niche describes the role and position of an organism in its ecosystem.
• It includes the habitat, food sources, environmental requirements, and interactions with other organisms.

Last verified on 01-11-2026

Explanation

• Glycolysis is the common initial stage of both aerobic and anaerobic respiration.
• It occurs in the cytoplasm and breaks one glucose molecule into two molecules of pyruvate, producing a net gain of 2 ATP and 2 NADH.
• In aerobic respiration, pyruvate is generally further broken down through aerobic pathways.
• In anaerobic conditions, it may undergo fermentation or other processes to regenerate NAD⁺.

Last verified on 27-10-2026

Explanation

• Cauliflower is an immature, compact flower head (inflorescence) used as a vegetable.
• It consists of many undeveloped flower buds packed closely together.
• The edible part is mainly the fleshy, immature inflorescence.
• Cauliflower belongs to the family Brassicaceae, which also includes cabbage, broccoli, and mustard.

Last verified on 27-10-2026

Explanation

• Pinus is a gymnosperm that produces abundant yellow pollen grains, which may be released in large quantities during pollination.
• The yellow pollen falling from pine trees can resemble a shower of yellow powder, giving rise to the term “sulphur shower.”
• Pinus is wind-pollinated, so its lightweight pollen grains are carried by air currents.

Last verified on 27-10-2026

Explanation

• A phyllode is a flattened, leaf-like modified petiole that performs photosynthesis.
• In plants such as Acacia, the true leaves may be reduced, while the flattened petiole performs the leaf’s photosynthetic function.
• Phyllodes help reduce water loss in some plants adapted to dry environments.

Last verified on 27-10-2026

Explanation

• A facultative parasite normally lives as a parasite but can also survive independently as a saprophyte by obtaining nutrients from dead and decaying organic matter.

Additional information:

• An obligate parasite depends on a living host to complete its life cycle or survive and reproduce.
• A facultative saprophyte is the opposite: it normally lives on dead organic matter but can become parasitic under suitable conditions.

Last verified on 27-10-2026