Explanation

• Tropical rainforests are among the most threatened ecosystems because of deforestation, agricultural expansion, logging, and human settlements.
• They contain exceptionally high biodiversity, so habitat destruction puts many plant and animal species at risk.
• The Amazon, Congo, and Southeast Asian rainforests are major tropical rainforest regions.

Last verified on 01-11-2026

Explanation

• Short-day plants require a long, uninterrupted dark period to flower.
• A flash of red light during the dark period interrupts it and inhibits flowering.
• Far-red light given immediately after red light can reverse the red-light effect and restore flowering.

Last verified on 01-11-2026

Explanation

• Red light promotes seed germination in many light-sensitive seeds through the pigment phytochrome.
• Phytochrome absorbs red light and changes into its active form (Pfr), which can stimulate germination.
• Far-red light can reverse this effect by converting active phytochrome back into its inactive form (Pr).

Last verified on 01-11-2026

Explanation

• Synecology is the branch of ecology that studies groups of organisms or communities and their relationships with the environment.
• It examines interactions among different species, such as competition, predation, and mutualism.

Additional information:

• Autecology studies an individual organism or a single species in relation to its environment.

Last verified on 01-11-2026

Explanation

• Domestic sewage and agricultural fertilizers are major sources of phosphate pollution in water bodies.
• Excess phosphates promote rapid growth of algae, causing eutrophication.
• Eutrophication can reduce dissolved oxygen in water and harm aquatic life.

Last verified on 01-11-2026

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