How many episodes of mass extinctions of species have occurred on earth since the origin and diversification of life?

The experiment of transforming principle was conducted on:

A single stranded DNA or RNA tagged with a radioactive probe is allowed to hybridize to its complementary DNA in a clone of cells followed by detection using __________.

Somaclones can be defined as:

In grass families, the cotyledon is called as:

Which one of the given assisted reproductive technologies (ART) involves transfer of fertilized egg into the fallopian tube?

Select the correct statements regarding the menstrual cycle in females:
(A) The first menstruation begins at puberty and is called menopause.
(B) Ovulation occurs mid-cycle (around day 14) when progesterone level is maximum.
(C) In absence of fertilization, corpus luteum degenerates and causes breakdown of endometrium, starting a new cycle.
(D) In humans, menstrual cycle stops around the age of 50 years.
Select the correct answer from the options given below:

\(\text { If } I=\int \frac{x}{x-\sqrt{x^2-4}} d x=\alpha x^3+\beta\left(x^2-4\right)^{\frac{3}{2}}+\gamma\) where \(\gamma\) is a constant of integration, then

The function \(f(x)=x^2-4 x+6\) is
(A) Strictly decreasing on \((-\infty, 2) \cup(2, \infty)\)
(B) Strictly increasing on ( \(2, \infty\) )
(C) Strictly increasing on \((-\infty, \infty)\)
(D) Strictly decreasing on \((-\infty, 2)\)
Choose the correct answer from the options given below :

The rate of a chemical reaction doubled for every \(10^{\circ} C\) rise in temperature. If the temperature is raised by \(50^{\circ} C\), the rate of reactions will be

Match List-I with List-II

List-I (Physical quantity)	List-II (Unit)
(A) Electric flux	(I) V m−1
(B) Polarisation	(II) kg m−1⁢ s−2
(C) Electric field	(III) V m
(D) Energy density	(IV) C m−2

Choose the correct answer from the options given below:

The enzyme used to treat a plant cell for isolation of DNA is:

Read the following passage carefully and answer the given questions
The earthworm is referred to as the farmer's friend. This is because they help in the breakdown of complex organic matter as well as in loosening of soil. Similarly, decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process is called decomposition. Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter, constitute detritus, which is the raw material for decomposition. Some of the steps in the process of decomposition are fragmentation, catabolism, leaching, humification etc.
Process of accumulation of dark coloured amorphous substance is called: