Explanation

• Digestion begins in the mouth, starting immediately when food is ingested.
• Both mechanical digestion (chewing) and chemical digestion (salivary amylase breaking down carbohydrates) 

Additional information:

• Mouth: Food is chewed and mixed with saliva that contains enzymes to break down carbohydrates.
• Esophagus: Food is swallowed and passes through the esophagus into the stomach.
• Stomach: Food is mixed with stomach acid and enzymes to break down proteins and fats.
• Small Intestine: Nutrients are absorbed into the bloodstream.
• Large Intestine: Water and electrolytes are absorbed, and waste is eliminated.

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Last updated by NS on 01 MAY 2026

Explanation

• The stratosphere is heated mainly by ozone.
• Ozone layer absorbs harmful ultraviolet (UV) radiation from the Sun.
• This absorption converts solar energy into heat.
• It causes warming in the stratosphere instead of cooling.
• This layer protects Earth from dangerous UV rays.

Last verified on 01-05-2026

Explanation

Composition of Air:

• Nitrogen → 78%
• Oxygen → 20.95%
• Argon → 0.93%
• Carbon dioxide → 0.04%
• Other gases → very small traces

Last verified on 30-04-2026

Explanation

• Vitamin A is essential for vision, skin health, and immune function.
• Its deficiency can lead to night blindness (poor ight vision) and other health problems.

Additional information:

• Dry skin and eyes
• Impaired immune function
• Poor wound healing
• Increased risk of respiratory and urinary tract infections

Last verified on 17-01-2026

Explanation

• Eccrine sweat glands help regulate body temperature.
• They are most densely found on palms and soles.
• These glands produce watery sweat for cooling.
• They are active throughout the body, especially in these areas.
• This helps maintain body temperature balance.

Last verified on 26-04-2026

Explanation

• Succus entericus is the digestive juice of the small intestine (ileum).
• It helps in the final digestion of food.
• It contains enzymes that break down nutrients.
• It completes the digestion process in the intestine.
• It is also called intestinal juice.

Last verified on 26-04-2026

Explanation

• Roentgen rays are also called X-rays.
• They are used to detect fractures and bone diseases.
• They pass through soft tissues but not bones clearly.
• Doctors use them in medical imaging (radiology).
• They were discovered by Wilhelm Roentgen.

Last verified on 26-04-2026

Explanation

• Ecology is the study of relationships between living organisms and their environment.
• It includes interactions among plants, animals, and surroundings.
• The term was introduced by Ernst Haeckel in 1866.
• It helps in understanding ecosystems and environmental balance.

Last verified on 25-04-2026

Explanation

• The Nobel Prize for the structure of DNA was awarded in 1962.
• The winners were James Watson, Francis Crick, and Maurice Wilkins.
• They discovered the double helix structure of DNA.
• This discovery revolutionized genetics and molecular biology.

Last verified on 25-04-2026

Explanation

• The longest cell in the human body is the nerve cell (neuron).
• Some neurons can extend up to 1 meter in length.
• They transmit impulses throughout the body.

Additional information:

• The smallest cell in the human body is the sperm cell (spermatozoon).
• It is measures approximately 4–5 micrometers (µm) in length.
• It is mainly consisting of a nucleus and a tail.

Last verified on 23-04-2026