Explanation

• The oesophagus is a muscular tube that connects the pharynx (throat) to the stomach.
• Its main function is to transport food from the pharynx to the stomach through peristalsis (wave-like muscle contractions).

Explanation

An element with 7 valence electrons needs 1 more electron to complete its octet.

Therefore, its valency is 1, as it tends to gain 1 electron during bonding.

Explanation

Fruit and vegetables are a good source of vitamins and minerals

 including vitamin C and potassium.

Explanation

Explanation

Explanation

DNA is the fundamental molecule that carries genetic information, forming the basis of heredity alongside chromosomes and genes.

It is the hereditary material in almost all organisms, encoding the instructions for building proteins and other important molecules.

Explanation

AB-positive blood type is known as the “universal recipient” because AB-positive patients can receive red blood cells from all blood types.

The blood group system was discovered by Austrian physician Karl Landsteiner in 1901.

He identified the ABO blood group system,

ND5-07-2023

Explanation

Explanation

Sound wave is a mechanical  wave.

Explanation

The pancreas is the enzyme “powerhouse” of digestion.

It produces the most important digestive enzymes,

which are those that break down carbohydrates, proteins, and fats.

the pancreas creates natural juices called pancreatic enzymes to break down foods.