Once puberty is reached in girls, ovaries begin to produce the female hormone, estrogen which helps in the development of breasts. Milk secreting glands or mammary glands develop inside the breasts.

During spring or rainy season, frogs and toads move to ponds and slow-flowing streams where the male and female come together and lay hundreds of eggs. A layer of jelly holds the eggs together and provides protection to them. The males deposits sperms over them which swims randomly in water. Fertilization takes place when the sperms come in contact with the eggs. Such type of external fertilization takes place in aquatic animals like fish, starfish, etc.

During rainy season, we see a flash of light in the clouds in the sky followed by a loud sound called lightning. Lightning is an electric discharge in the atmosphere between oppositely charged clouds. Lightning is produced by the electric charges in the sky. The electric nature of lightning was established by a scientist named Benjamin Franklin.

Before the arrival of Lord Cornwallis, the police was under the authority of the zamindars and thus reported to them. Lord Cornwallis brought the police system under the Crown's governance and created a system under which 'thanas' headed by police inspectors were constituted at the level of districts, and such thanas reported to the superintendent of police (S.P.).

Endoplasmic reticulum is a continuous membrane, which is present in both plant cells, animal cells and absent in prokaryotic cells. It is the membrane of network tubules and flattened sacs, which serves a variety of functions within the cell. The space, which is present in the endoplasmic reticulum, is called as the lumen.  
The major functions of Endoplasmic reticulum are:

1. It is mainly responsible for the transportation of proteins and other carbohydrates to another organelle, which includes lysosomes, Golgi apparatus, plasma membrane, etc.
2. They play a vital role in the formation of the skeletal framework.
3. They provide the increased surface area for cellular reactions.
4. They help in the formation of nuclear membrane during cell division.
5. They play a vital role in the synthesis of proteins, lipids, glycogen and other steroids like cholesterol, progesterone, testosterone, etc.

xy -pq + qy - px
= xy - px + qy - pq
= x(y - p) + q(y - p)
= (x + q) (y - p)

After the Lok Sabha elections, a list is prepared showing how many MPs belong to each political party. For a political party to form the government, they must have a majority of elected MPs. Since there are 543 elected (plus 2 nominated) members in Lok Sabha, to have a majority a party should have at least half the number i.e. 272 members or more. The Opposition in Parliament is formed by all the political parties that oppose the majority party/coalition formed. The largest amongst these parties is called the Opposition party.
The members of the Rajya Sabha are elected by the elected members of the Legislative Assemblies of various states. There are 233 elected members plus 12 members nominated by the President.

Both Firdous Kanga and Stephen are extraordinary people because they are disabled. Stephen Hawking is one of the greatest scientists of our time. He suffers from a form of paralysis that confines him to a wheelchair, and allows him to ‘speak’ only by punching buttons on a computer, which speaks for him in a machine-like voice. Firdaus Kanga is a writer and journalist who lives and works in Mumbai. Kanga was born with ‘brittle bones’ that tended to break easily when he was a child. Like Hawking, Kanga moves around in a wheelchair.

Diatoms are unicellular algae that are well-known for the spectacular design of their cell walls. The di- atom cell wall is made of amorphous, hydrated silici- umdioxide (silica) which is associated with proteins and polysaccharides. A cell wall is a fairly rigid layer surrounding a cell located outside of the plasma membrane that provides additional support and protection. They are found in bacteria, archaea, fungi, plants, and algae. Animals and most other protists have cell membranes without surrounding cell walls.