Sex determination in Human

Sex determination in Human : In human male sex chromosome is XY, where in female sex chromosome is XX.

During gamete (sperm) formation in male half of the sperm contains X chromosome while other half contain Y chromosome. In female all gametes contain only one type of chromosome that is X.

Sex determination in Human

Thus when a male gamete i.e. sperm carrying X chromosome fertilize an ova, the zygote develope into female. When a sperm carrying Y chromosome fertilizes an egg, zygote develops into male.

First in the World : Volume VI

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»»    First city to be attacked with Atom Bomb : Heroshima (Japan)

»»    First Woman Prime Minister of a country : S. Bhandarnayke (Sri Lanka)

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Father of modern Chemistry

Question : What is Chemistry?

Answer : Chemistry is the branch of science which deals with the composition of matter and also the Physical and Chemical characteristics associated with the different material objects.

Question : Who is the father of modern Chemistry?

Answer : French chemist, "Lavoisier (1743-1793)" is regarded as the father of modern chemistry.

Lavoisier (1743-1793)

Razia Sultana - only Muslim lady ever ruled India

Razia Sultana - only Muslim lady ever ruled India : Though Iltumish had nominated his daughter Razia as the successor, the nobles placed Ruknuddin Firoz as the throne. However, Razia got rid of Ruknuddin and ascended the throne.

Razia was the "first and only Muslim lady who ever ruled India". Razia was popular among the people but was not acceptable to the nobles and theologians.

Razia further offended the nobles by her preference for an Abyssian slave Yakut. Soon after her accession, the governors of Multan, Badaun, Hansi and Lahore openly revolted against her.

There was a serious rebellion in Bhatinda. Altunia, governor of Bhatinda refused to accept suzerainity of Razia. Razia accompanied by Yakut marched against Altunia.



(Grave of Razia Sultan)

However, Altunia got Yakut murdered and imprisoned Razia. Subsequently, Razia married Altunia and both of them marched towards Delhi.

In 1240 AD, Razia became the victim of a conspiracy and was assassinated near Kaithal, Haryana.

Asteroids

Asteroids : Asteroids are also known as minor planets. They are objects that revolve around the Sun. They are mostly found between the orbits of Mars and Jupiter.

Asteroids are a belt of debris which failed to assemble into planets and keeps on revolving around the Sun. This has come to be called as 'asteroid belt'.

An Asteroid

More than 5000 asteroids have been identified. Asteroids may be spherical, elongated or irregular in shape. All asteroids rotate on their axis, every 5 to 20 hours. Certain asteroids may have satellites.

Trojan asteroids are found in two clouds moving in the orbit of Jupiter, one moving ahead of it and the other moving behind it.

Rotating Asteroid

"Scientits believe that these asteroids occupy a place where a planet could have exited but was prevented from its formation by the disruptive gravitational force of the giant planet, Jupiter."