21.

The first stable product of fixation of atmospheric nitrogen in the leguminous plant is 

• NO₂^-

• ammonia

• NO₃^-

• glutamate

Macromolecule chitin is

• Nitrogen-containing polysaccharide

• Phosphorous containing polysaccharide

• Sulphur containing polysaccharide

• Simple polysacchaaride

Following are the two statements regarding the origin of life.

1. The earliest organisms that appeared on the earth were non-green and presumably an aerobes.
2. The first autotrophic organisms were the chemoautotrophs that never released oxygen of the above statements which on of the following options is correct?

• II is correct, but I is false

• Both I and II are correct

• Both I and II are false

• I is correct, but II is false

The structures present in the roots to absorb water and minerals is

• Epidermal extensions

• Hypodermis

• Endodermis

• Epidermal appendages

Nitrogen-fixation in root nodules of Alnus is brought about by

• Bradyrhizobium

• Clostridium

• Frankia

• Azorhizobium

Many elements are found in living organisms either free or in form of compounds. One of the following is negligible is living organisms

• Silicon

• Magnesium

• Iron

• Sodium

Which of the following is non-symbiotic nitrogen fixer organism?

• VAM

• Azotobacter

• Anabaena

• Rhizobium

Which of the following is responsible for biological nitrogen-fixation?

• Nife gene

• Nitrogenase

• Yeast alanin tRNA synthetase

• RNA synthetase

 ‘Sun basket’ is

• The device to utilize sun rays directly to meet the requirement of heat energy

• The sufficient amount of sunlight stored in a cell

• A device of taking a sunbath

•  All of the above

Chlorosis is produced in the leaves due to the deficiency of Fe, Mg, Mn, S or N of these essential elements, those that are exclusive constituents of chlorophyll molecule are

• Fe, S

• N,S

• Mg, S

• Mg, N