Explanation

White Blood Cells (WBCs), also known as leukocytes, are a vital part of the immune system.

They protect the body from infectious diseases and foreign invaders by identifying and eliminating pathogens.

Such as bacteria, viruses, and other foreign substances.

Explanation

Demography is the statistical study of the human population,

Including aspects such as size, structure, distribution, and dynamics.

It examines factors like birth and death rates, migration, age, sex, and occupation, among others.

انسانی آبادی کا شماریاتی مطالعہ ڈیموگرافی کہلاتا ہے۔

Explanation

Goiter is caused by iodine deficiency.

It results in an enlarged thyroid gland.

Iodine deficiency can cause mental retardation in children.

Particularly if the deficiency occurs during fetal development or early childhood.

This is because iodine is essential for brain development and thyroid function.

The effects of the thyroid come from two iodine-containing hormones.

Explanation

The cerebrum is the largest part of the brain.

The largest part of the brain, the cerebrum has two hemispheres (or halves).

The cerebrum controls voluntary movement, speech, intelligence, memory, emotion, and sensory processing.

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RY4-12-2022

Explanation

Caffeine occurs naturally in the tea plant,

Camellia sinensis, so all brewed tea contains some caffeine. 

Tea leaves contain 3.5% caffeine,

while

Coffee beans have 1.1–2.2%.

Explanation

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

Albert Einstein is one of the most influential physicists of the 20th century.

In 1905 Einstein published four landmark papers in physics.

Einstein was awarded the Nobel Prize for his work on: Special theory of relativity

Albert Einstein received his Nobel Prize one year later, in 1922.

Explanation

The SI unit of temperature as per the International System of Units is Kelvin.

It is represented by the symbol  K.

Note:

Celsius is currently a derived unit for temperature in the SI system, Kelvin is the base unit.

Explanation

Solar cells, also known as photovoltaic cells, convert solar energy (sunlight) directly into electrical energy.

They work by using semiconductor materials to absorb photons from sunlight and release electrons, generating electricity.