Which of the following statements about DNA is/are correct?

1) DNA is the hereditary material of all living organisms.

2) All segments of DNA code for the synthesis of proteins.

3) Nuclear DNA is double helical with two nucleotide chains which run anti-parallel.

4) DNA is also found in mitochondria.

Select the correct answer using the code given below :

When heat rays are reflected from Earth, gases like Carbon dioxide, Nitrous oxide do not allow them to escape back to the space causing our planet to heat up. These gases are known as

All life forms contain "molecules of life". These are -

Leprosy is caused by

Identify the compound which is when consumed in very small quantities, can cause death. It also causes blindness by affecting the optic nerve.