The major portion of the dry weight of plants comprises of:

1. Nitrogen, phosphorus, and potassium

2. Calcium, magnesium, and sulphur

3. Carbon, nitrogen, and hydrogen

4. Carbon, hydrogen, and oxygen

It is said that elemental composition of living organisms and that of inanimate objects (like earth’s crust) are similar in the sense that all the major elements are present in both. Then what would be the difference between these two groups? Choose a correct answer from among the following.
 

Many elements are found in living organisms either free or in the form of compounds. One of the following is not found in living organisms.

1. Silicon

2. Magnesium

3. Iron

4. Sodium

Phospholipids are esters of glycerol with:
 

Which of the following is the simplest amino acid?
1. Alanine
2. Asparagine
3. Glycine
4. Tyrosine

Nucleotides are building blocks of nucleic acids. Each nucleotide is a composite molecule formed by -

1. Base-sugar-OH

2. Base-sugar-phosphate

3. Sugar-phosphate

4. (Base-sugar-phosphate)_n

Amino acids have both an amino group and a carboxyl group in their structure. Which amongst the following is an amino acid?

1. Formic acid

2. Glycerol

3. Glycolic acid

4. Glycine

An amino acid under certain conditions has both positive and negative charges simultaneously in the same molecule. Such a form of amino acid is called

1. acidic form

2. basic form

3. aromatic form

4. zwitterionic form