Questions

Gene is a hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism.

In short it is a piece or segment of chromosome.

Genes undergo mutation when their DNA sequence changes. 

Production costs to an economist reflect opportunity costs.

The purpose of the Preamble is to clarify

1. who has made the Constitution,

2. what is the ultimate sanction behind it,

3. what are its goals and objectives,

4. what is its source (and)

5. what is the nature of the polity which is sought to be established by the Constitution.

Actually, the preamble is the opening statement to the United States Constitution.

The words in the Preamble ::

 'We the people of India, in our Constituent Assembly, do hereby adopt, enact and give to ourselves this Constitution'.

An Anchor.

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.

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