Explanation

The 100 percent pure gold is 24-carat gold.

Lower cartages contain less gold 18-carat gold contains 75 percent gold and 25 per cent other metals, often copper or silver.

Carat is the unit of measurement for the physical weight of diamonds/Gold.

ND16-8-2023

Explanation

Origin of species using Natural Selection was the work of Charles Darwin.

It was published on 24 November 1859,

..

Charles Darwin's discoveries included.

four different species of giant ground sloth (some of the largest land mammals ever to have lived), a gomphothere,

and the remains of an extinct horse.

ND16-8-2023

Explanation

Lactometer is used for milk

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A lactometer is an instrument that is used to check for the purity of milk by measuring its density.

 lactometer works on the principle of gravity of milk.

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Explanation

The percentage of oxygen in the air is about 20.95%.

The air is made up of many gases, including oxygen, nitrogen, argon, and carbon dioxide

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Nitrogen

Nitrogen is the most abundant gas in the air, making up about 78% of it. 

Argon

Argon is the third most abundant gas in the air, making up about 0.93% of it. 

Carbon dioxide

Carbon dioxide is present in trace amounts in the air, making up about 0.04% of it. 

Explanation

Ronald Ross was a medical doctor who received the Nobel Prize for Physiology or Medicine in 1902 for his work on the transmission of malaria.

He belonged to the British.

Explanation

Explanation

Charles Darwin is often credited with "discovering" evolution.

He wrote about evolution from 1748 to 1859

It was the year when he published On the Origin of Species.

Explanation

Vitamin A deficiency can be caused by inadequate intake, poor fat absorption, or liver disease.

Deficiency impairs immunity and blood formation, causing skin rashes and typical eye symptoms (xerophthalmia, night blindness, etc.).

Carrot is a good source of Vitamin A.

Night blindness means رات کا اندھا پن 

Explanation

The heart consists of four chambers in which blood flows.

Blood enters the right atrium and passes through the right ventricle.

The right ventricle pumps the blood to the lungs where it becomes oxygenated.

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۔