Explanation

The retina is a thin layer of tissue that lines the back of the eye on the inside.

It is located near the optic nerve.

The purpose of the retina is to receive light that the lens has focused,

convert the light into neural signals,

and send these signals on to the brain for visual recognition

Explanation

Mercury is the only metal that is liquid at normal temperatures. 

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Chemical compounds of mercury have found uses in batteries, in biocides in the paper industry, in paints, and on seed grain, as antiseptics in pharmaceuticals, as reagents in laboratories, and as catalysts.

Four other elements are liquids slightly warmer than room temperature.

They are:

• francium
• cesium
• gallium
•  rubidium

ND31-12-2022

SH10-8-2023

Explanation

Light Year is the distance that light can travel in one year.

The distance light travels in one year is known as light year.

Explanation

The stratospheric ozone layer is Earth's “sunscreen”  protecting living things from too much ultraviolet radiation from the sun.

Oxygen layer in the atmosphere

Ozone protects us from the harmful ultraviolet radiation of the sun.

Ozone formula: O3

The ozone layer lies approximately 15-40 kilometers (10-25 miles) above the Earth's surface, in the stratosphere.

The ozone layer is depleting: Air pollution

ND17-7-2023

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Explanation

The molecules are most tightly packed in solid state because of the strong intermolecular forces of attraction.

Explanation

Karl Landsteiner discovered ABO blood group system.

He was an Austrian scientist.

Karl Landsteiner received Noble Prize in 1930

Blood Group System was discovered in 1900.

Explanation

Explanation

Hemoglobin is the respiratory protein of many arthropods

Explanation

Explanation

 Zinc:

1. Loss of appetite
2. stunted growth
3. delayed healing of the wound
4. hair loss
5. diarrhea

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ND2-2-2023