Which one of the following gases can deplete the ozone layer in the upper atmosphere?

In an experiment,four quantities $a, b, c$ and $d$ are measured with percentage errors of $1\%, 2\%, 3\%$ and $4\%$ respectively. Quantity $P$ is calculated as $P = \frac{a^3 b^2}{cd}$. The percentage error in the measurement of $P$ is .......... $\%$

Which of the following statements is incorrect regarding viruses?

Which is the lightest gas?

Let $\alpha$ and $\beta$ be the roots of the equation $x^2-x-1=0$. If $p_{k}=(\alpha)^{k}+(\beta)^{k}, k \geq 1$,then which one of the following statements is not true?

Which one of the following pairs is correctly matched with regard to the codon and the amino acid coded by it?