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

• Bradyrhizobium

• Clostridium

• Frankia

• Frankia

The two subunits of ribosome remain united at a critical ion level of

• Copper

• Manganese

• Manganese

• Manganese

Which one of the following elements is not an essential micronutrient for plant growth?

• Mn

• Zn

• Cu

• Cu

Examination of blood of a person suspected of having anaemia, shows large, immature, nucleated erythrocytes without haemoglobin. Supplementing his diet with which of the following is likely to alleviate his symptoms?

• Thiamine

• Folic acid and cobalamine

• Riboflavin

• Riboflavin

Sulphur is an important nutrient for optimum growth and productivity in

• pulse crops

• cereals

• fibre crops

• fibre crops

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

120.

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

• Bradyrhizobium

• Clostridium

• Frankia

• Azorhizobium