Explanation

• The carinal canal forms due to the disintegration of protoxylem elements in the stem of Equisetum (horsetail).
• It is located within each vascular bundle, beneath the ridge of the stem.
• The vallecular canals are different cavities located beneath the grooves of the stem.
• They are associated with the cortex.

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

Explanation

• Exhaled air contains about 16% oxygen.
• Because the body absorbs some oxygen during gas exchange in the lungs.
• Atmospheric air contains approximately 21% oxygen.
• Exhaled air contains approximately 4% carbon dioxide, compared with about 0.04% in atmospheric air.

Last verified on 27-10-2026

Explanation

• Silverfish is a small, wingless insect belonging to the phylum Arthropoda and class Insecta.
• It has a flattened, elongated body covered with silvery scales and three tail-like appendages.

Last verified on 27-10-2026

Explanation

• Gene cloning is a technique used to produce multiple identical copies of a specific gene or DNA sequence.
• The cloned gene can be introduced into host cells, which multiply and produce copies of the desired DNA.

Last verified on 27-10-2026

Explanation

• Tropical rain forests support exceptionally high biodiversity but face severe threats from deforestation, agricultural expansion, logging, and habitat destruction.
• Subtropical rain forests are also threatened by habitat loss, land conversion, and human activities.

Last verified on 27-10-2026

Explanation

• A pellicle is a supportive outer covering found in certain unicellular organisms.
• It helps maintain their shape while allowing flexibility to varying degrees.
• Amoeba verrucosa is identified as having a thicker, wrinkled, pellicle-like covering.

Last verified on 27-10-2026

Explanation

• Cichlids are freshwater fish found in several lakes, including Lake Victoria in Africa, which is famous for its diverse cichlid species.
• Overfishing, waste pollution, and agricultural runoff can damage aquatic ecosystems and contribute to the decline or extinction of fish species.
• Agricultural runoff may carry fertilizers and pesticides into lakes, causing eutrophication, reducing oxygen levels, and harming aquatic life.

Last verified on 27-10-2026

Explanation

• The edible part of cauliflower is a compact cluster of immature flower buds arranged in a branched inflorescence.
• The flower buds are harvested before they develop into fully open flowers.
• Cauliflower belongs to the family Brassicaceae, which also includes cabbage, broccoli, and mustard.

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