A student has to perform the experiment "To identify the different parts of an embryo of a dicot seed." Select from the following an appropriate group of seeds:

A student takes four test tubes marked P, Q R and S of 25 mL capacity and fills 10 mL of distilled water in each. He dissolves one spoon full of four different salts in each as-KCl in P, NaCl in Q CaCI₂ in Rand MgCI₂ in S. He then adds about 2 mL of a sample of soap solution to each of the above test tubes. On shaking the contents of each of the test tubes, he is likely to observe a good amount of lather (foam) in the test tubes marked:

Consider the following comments about saponification reactions:

(I) Heat is evolved in these reaction.

(II) For quick precipitation of soap sodium chloride is added to the reaction mixture.

(III) Saponification reactions are special kind of neutralization reactions.

(IV) Soaps are basic salts of long chain fatty acids.

The correct comments are:

Which of the following is a correct set of homologous organs?

A student obtained a sharp image of a candle flame placed at the distant end of the laboratory table on a screen using a concave mirror to determine its focal length. The teacher suggested him to focus a distant building about 1km far from the laboratory, for getting more correct value of the focal length. In order to focus the distant building on the same screen the student should slightly move the