In some members of which of the following pairs of families, pollen grains retain their viability for months after release ?

Ten E.coli cells with \({ }^{15} N\) - dsDNA are incubated in medium containing \({ }^{14} N\) nucleotide. After 60 minutes, how many E.coli cells will have DNA totally free from \(15\,N\) ?

Assertion \((A):\) A person goes to high altitude and experiences 'altitude sickness' with symptoms like breathing difficulty and heart palpitations. Reason \((R):\) Due to low atmospheric pressure at high altitude, the body does not get sufficient oxygen. In the light of the above statements, choose the correct answer from the options given below.

Identify the correct statement with regard to \(G _{1}\) phase \((Gap\,1)\) of interphase.

Which of the following statements about methanogens is not correct?

All the components of the nodal tissue are autoexcitable. Why does the SA node act as the normal pacemakar?

The blue and white selectable markers have been developed which differentiate recombinant colonies from non-recombinant colonies on the basis of their ability to produce colour in the presence of a chromogenic substrate.

Given below are two statements about this method:
Statement I : The blue coloured colonies have DNA insert in the plasmid and they are identified as recombinant colonies.

Statement II : The colonies without blue colour have DNA insert in the plasmid and are identified as recombinant colonies.

In the light of the above statements, choose the most appropriate answer from the options given below:

If an electron in a hydrogen atom jumps from the \(3^{rd}\) orbit to the \(2^{nd}\) orbit, it emits a photon of wavelength \(\lambda\). when it jumps from the \(4^{th}\) orbit to the \(3^{rd}\) orbit, the corresponding wavelength of the photon will be

A liquid does not wet the solid surface if angle of contact is

Lecithin, a small molecular weight organic compound found in living tissues, is an example of:

For Young's double slit experiment, two statements are given below : Statement \(I:\) If screen is moved away from the plane of slits, angular separation of the fringes remains constant. Statement \(II:\) If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases. In the light of the above statements, choose the correct answer from the options given below :

The ovule of an angiosperm is technically equivalent to

Consider the molecules \(CH_4, NH_3\) and \(H_2O.\) Which of the given statements is false?