Explanation

• The greenhouse effect is an environmental problem caused by the increasing amount of carbon dioxide (CO2) in the atmosphere.
• Primarily due to human activities such as burning fossil fuels, deforestation, and land-use changes.
• This excess CO2 traps heat and leads to global warming and climate change.

Explanation

Short-sightedness is caused due to elongation of the eyeball

 It also may result when the curve of the cornea is too steep. 

The messages sent from the retina to the brain are perceived as blurry

Explanation

In the metric system, the SI unit of length is a meter which is

defined as: “The length of the path traveled by light in a vacuum within 1⁄299792458 seconds.”

Common symbols: l

ND18-9-2023

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

Explanation

• The nervous system is the body system that controls and coordinates the functions of all other organ systems.
• It allowing for integration and regulation of various bodily functions.
• It consists of the brain, spinal cord, nerves, and sensory organs.

Explanation

Gregor Mendel (from Austria) is called the Father of Genetics for his experiments on pea plants.

He discovered the basic principles of heredity and inheritance through his work.

Explanation

The wind is used to produce electricity by converting the kinetic energy of air in motion into electricity.

Wind energy is the energy obtained from the force of the wind.

The unit of wind is: joule

Explanation

• Ozone gas is a molecule made up of three oxygen atoms, with the chemical formula O3.
• This is different from ordinary oxygen, which has the chemical formula O2.

Explanation

• When blue litmus paper is dipped in an acid, it turns red.
• This is because the acid changes the color of the litmus paper from blue to red.

Note: When red litmus paper is dipped in a base, it turns blue.

Explanation

Chromosomes are made up of:

• Nucleic acid (DNA or RNA)
• Proteins (histones and non-histone proteins)

A chromosome is made up of proteins and DNA organized into genes.

Each cell normally contains 23 pairs of chromosomes.