Explanation

• The kidney is an important organ responsible for filtering blood and forming urine.
• Its structural and functional unit is the nephron.
• Each kidney contains millions of nephrons.
• They perform filtration, reabsorption, and secretion.

Last verified on 23-04-2026

Explanation

In fish, ammonia is the chief excretory waste.

Fish excrete ammonia directly into the water through their gills.

Ammonia is toxic, but since fish live in water it gets diluted quickly, making it safe for excretion in this form.

Explanation

The longest bone is the Femur (thigh bone) and the shortest one is the Stapes (one of the 3 small bones inside the ear).

The largest and broadest is the hip bone or pelvis.

The lowest part of the backbone called the sacrum

The smallest bone is the stirrup (stapes) 

The strongest bone for its size is the lower jaw or mandible.

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Explanation

The cell is the smallest unit of life.

Cells are called ‘structural’ and ‘functional’ units for a reason.

Cells are made of molecules which are in turn made up of atoms.

“Cell is the unit of LIFE” is that a cell is the smallest living entity in a living system.

Explanation

Instead of nostrils, insects breathe through openings in the thorax and abdomen called spiracles.

Insects that are diapausing or non-mobile have low metabolic rates and need to take in less oxygen.

Insects exchange oxygen and carbon dioxide through spiracles (noted by circle)

Explanation

Bryophytes such as mosses and algae are non-vascular plants.

They do not possess true roots, stems and leaves.

Xylem and phloem are absent. Bryophytes include liverworts, hornworts and mosses.

Explanation

Autumn leaves appear red and yellow because carotenoids are revealed.

This happens when chlorophyll breaks down in response to less sunlight.

Shown is a colour photograph of bright red and yellow flowers with green stems and leaves.

Explanation

Transpiration is ultimately the main driver of water movement in xylem, combined with the effects of capillary action.

The cohesion-tension model works like this: Transpiration (evaporation) occurs because stomata in the leaves are open to allow gas exchange for photosynthesis.

Explanation

The living simple tissue that provides support to the growing parts of a plant is collenchyma.

Collenchyma is a simple permanent tissue.

The cells are thickened at the corners due to the deposition of cellulose, hemicellulose, and pectin.

It provides mechanical support to the young, growing parts of the plant.

Explanation

The branch of botany that deals with the classification and evolutionary study of plants is called Systematics, which includes Plant Taxonomy,