Questions

The Bantu were comprised of more than 500 ethnic groups of Africa for migrations. The Bantu were experts in the form of iron metallurgy. 

Ionic bonding is a type of chemical bond in which valence electrons are lost from one atom and gained by another.. This bond generates two oppositely charged ions.

In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.

Example ::

One example of an ionic bond is the formation of sodium fluoride, NaF, from a sodium atom and a fluorine atom. In this reaction, the sodium atom loses its single valence electron to the fluorine atom, which has just enough space to accept it. The ions produced are oppositely charged and are attracted to one another due to electrostatic forces.

Core of earth is also known as Barysphere.

Cerebrum is the largest region of the brain.

The passage is based on economic development of the bank. It says that the economic growth of the bank in terms of the money is based on the cost of settlement. If this cost is reduced amongst the countries then the flow of payment will be maintained or vice versa. It is nowhere mentioned in the passage about rural or urban areas so we will take a general context. Hence option B is the correct option.

The purines are bases in the DNA. The two purines in DNA are Adenine and Guanine. These two purines forms hydrogen bonds with their complimentary pyrimidines such as Thymine and Cytosine to keep the two rails of the DNA molecule together.