Explanation

H5N1 is a type of influenza virus

Causes a highly infectious

Also known as avian influenza.

Occurs mainly in birds, is highly contagious among birds, and can be deadly, especially in domestic poultry

Explanation

Wilhelm Johannsen coined the term “gene” in 1909

Johannsen created "gene" from the Greek word genos, meaning "birth" or "race".

He  was a Danish botanist and geneticist

 He is best known for coining the terms gene, phenotype, and genotype, and for his 1903 "pure line" experiments in genetics.

Born: 3 February 1857, Elsinore, Denmark

Died: 11 November 1927 (aged 70) Copenhagen, Denmark

Explanation

One barrel of petroleum is a standard unit of measurement in the oil industry.

It equals 42 US gallons, which is approximately 159 liters.

In cubic meters, it is roughly 0.159 m³.

The UK gallon is larger, so one barrel equals about 34.97 UK gallons.

This unit is used worldwide for oil production, trading, and pricing

Explanation

The medulla oblongata is located in the brainstem.

It regulates involuntary functions such as heartbeat, breathing, and blood pressure.

The cardiac center within the medulla controls heart rate and force of contraction.

It receives signals from the autonomic nervous system (sympathetic and parasympathetic).

Explanation

The troposphere is the lowest layer of Earth’s atmosphere.

It extends from the Earth’s surface up to about 8–15 km (varies with latitude).

All weather phenomena like rain, clouds, and storms occur in this layer.

It contains approximately 75–80% of the atmosphere’s mass.

The temperature in the troposphere decreases with altitude.

Explanation

Magma is molten rock beneath the Earth’s surface.

When it erupts through a volcano or reaches the surface, it is called lava.

Lava cools and solidifies to form igneous rocks.

The flow of lava can create volcanic landforms like lava plateaus and volcanic cones.

Lava temperature ranges from 700°C to 1,200°C, depending on its composition.

Explanation

Metamorphic rocks are formed from pre-existing rocks (igneous, sedimentary, or older metamorphic rocks).

They are changed by high heat and/or pressure without melting.

Common examples include marble (from limestone) and gneiss (from granite).

The process is called metamorphism, meaning “change in form.”

Explanation

Explanation

Blood circulation rate in human arteries varies, fastest in the aorta (around 30-40 cm/s) 

In capillaries, the speed drops significantly to allow nutrient and gas exchange.

Blood velocity is highest in arteries, moderate in veins, and slowest in capillaries.

Proper circulation speed ensures efficient delivery of oxygen and nutrients throughout the body.

Explanation

Chromosomes are thread-like structures found in the nucleus of a cell.

They carry genetic information in the form of DNA.

Humans have 46 chromosomes (23 pairs) in each cell.

Chromosomes determine hereditary traits passed from parents to offspring.

They play a key role in cell division, growth, and reproduction.