Questions

A primary key is a special relational database table column or combination of columns designated to uniquely identify all table records. That is, A primary key is a column or set of columns in a table that uniquely identifies tuples (rows) in that table.

A primary key, also called a Primary Keyword.

Main Features Primary key are ::

It must contain a unique value for each row of data.

It cannot contain null values.

In 1952, Waksman was awarded the Nobel Prize in Physiology or Medicine in recognition "for his discovery of streptomycin," the first antibiotic active against tuberculosis.

Hedging is a tool to minimize the risks. It is thus like an 'insurance' where one pays a premium but gets an assured amount in case of some uncertain event to the extent of the loss actually suffered on an equally opposite position for which the hedge was done. Thus, hedger is different from arbitrageur and speculators, as the intention here is not to maximize the profit but to minimize the loss.

E.g. In Capital Markets, suppose an investor has an equity portfolio of Rs. 2 lacs and the portfolio consists of all the major stocks of NIFTY. He thinks the market will improve in the long run but might go on a downside in the shortrun. NIFTY today stands at 4300. To minimize the risk of downfall, he enters into an option contract by buying NIFTY-PUT of strike 4300 at a premium of, say, Rs. 100. Thus, the actual amount paid is Rs. 5,000(lot size of NIFTY is 50). Also, the number of NIFTY-PUTs to be bought will vary on the beta of the portfolio so as to completely hedge the positon. 

Allows for expansion or contraction of the trachea. Hence, so large masses of food can pass through the esophagus during swallowing.

All enzymes are proteins but all proteins are not enzymes since, enzymes are subset of proteins.

Airtel Payments Bank is the first payment bank in India. A payments bank is a new category of banks conceptualized by the Reserve Bank of India, which operates at a smaller scale than an actual bank and doesn't involve any credit risk. It can carry out most banking operations but can't advance loans or issue credit cards.

The RBI as of date has given licences to 11 payments bank of which six are currently operational. These include

1. Aditya Birla Payments Bank,
2. Airtel Payments Bank,
3. India Post Payments Bank,
4. Fino Payments Bank,
5. Jio Payments Bank (and)
6. Paytm Payments Bank.

Allotropes are different structural modifications of an element, that is, each of two or more different physical forms in which an element can exist.

Carbon is capable of forming many allotropes due to its valency. Well-known forms of carbon include charcoal, diamond, graphite, buckminsterfullerene and graphene.

Hence, Ethylene is not an allotrope of Carbon.