Explanation

The frequency of AC (Alternating Current) supply in Pakistan is typically 50 Hertz (Hz).

AC electricity alternates back and forth in a direction 50 times per second

Explanation

We use Preposition During to say when something happens.

During this year, During this weekend, During this decade etc.

Explanation

Natural rubber is primarily composed of polyisoprene, a polymer made up of isoprene monomers.

Isoprene (2-methyl-1,3-butadiene) is a diene compound that polymerizes to form the long chains found in natural rubber.

Explanation

The ozone hole happens when the protective ozone layer in the stratosphere above the South Pole begins to thin every September.

All Important Questions Related to "OZONE"

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

Solar PV cells generate electricity by absorbing sunlight and using that light energy to create an electrical current.

There are many photovoltaic cells within a single solar panel, and the current created by all of the cells together adds up to enough electricity to help power your home

Explanation

Thymine is the nitrogenous base which is not present in RNA

Thymine is one of the four nucleobases found in DNA (along with adenine, guanine, and cytosine)

Whereas RNA contains uracil (U) instead of thymine.

RNA uses uracil as a complementary base to adenine during transcription,

while DNA uses thymine as a complementary base to adenine during replication.

Explanation

 Convection is the transfer of heat through the movement of a fluid, meaning it occurs in liquids and gases. 

Liquids: In liquids, warmer, less dense molecules rise, carrying heat with them. 

Gases: Similarly, in gases, hot molecules move more readily, transferring heat through the space

Explanation

 Closed System:

In a closed system, social status is largely determined at birth and individuals have limited or no ability to move up or down the social hierarchy. 

Examples of Closed Systems:

Traditional caste systems and feudal estate systems are examples of closed systems where social mobility is severely restricted

Explanation

Post-translational modifications are processes that occur after protein synthesis, and they are essential for the functional maturation and regulation of proteins.

These modifications, such as:

• adding carbohydrate groups (glycosylation)
• phosphate groups (phosphorylation),
• predominantly take place in the endoplasmic reticulum (ER) 
• the Golgi apparatus.

The ER is involved in the initial modifications and folding of proteins,

While the Golgi apparatus further processes and sorts proteins for their final destinations. 

Explanation

The reason the Earth is described as blue is because of the large oceans on its surface, which are blue.

From space, Earth looks like a blue marble with white swirls.

Some parts are brown, yellow, green, and white.

The blue part is water.

Water covers most of Earth.

ND23-9-2023