A.

Molybdenum

Molybdenum is absorbed as molybdate by plants. It is involved in nitrogen metabolism including nitrogen fixation. It is a component of enzyme nitrogenase and acts as an enzyme activator. Its deficiency cause chlorosis and necrosis, whiptail of cauliflower and premature leaf fall. 
Copper is absorbed by the plant in ionic form. Its deficiency causes necrosis, die back in Citrus, reclamation in legumes.
Manganese is absorbed by the plants as a bivalent ion. It acts as the enzyme activator. Its deficiency causes interveinal chlorosis as well as yellowing of starch and their subsequent degenerate. 
Zinc is needed for biosynthesis of IAA and also acts as the enzyme activator. Its deficiency causes chlorosis, little leaf, rosette, the white bud of maize and mottling of leaves.

A.

Photolysis of water

Photolysis of water requires light energy, an Oxygen-Evolving Complex (OEC) and electron carrier 1/2. OEC complex was formerly called Z-enzyme. It has four Mn ions. Light energy brings about changes in Mn (Mn⁺²,  Mn³⁺,  Mn⁺⁴) which helps in removing electrons from OH- component of water forming oxygen. Liberation of oxygen also requires Cl^- and Ca^+2.

C.

Golden rice

Golden rice is a variety of Oryza sativa (rice) produced through genetic engineering to biosynthesize Beta-acetone, a precursor of vitamin-A in the edible part of rice (i.e., endosperm). The research that led golden rice was conducted with the goal of helping children who suffer from vitamin-A deficiency. Because many children in countries where there is a dietary deficiency in vitamin-A rely on rice as a staple food, the genetic modification of rice to produce the vitamin-A precursor beta-carotene is seen as a simple and less expensive alternative to vitamin supplements. 

A.

Leghaemogolobin

During biological nitrogen fixation, inactivation of nitrogenase  by oxygen poisioning is prevented by leghaemoglobin.
It is a  red-pigment that is filled outside the peribacteroid space in the cytosol of nodule cells. It has the ability to combine very rapidly with oxygen and thus acts a very efficient O₂ scavenger. 

D.

Iron compounds

Anaemia refers to any condition in which there is an abnormally low haemoglobin concentration and/or blood cell count. The most common cause is deficiency of iron which is an essential element of haemoglobin molecule.
Thus, the iron compounds in the diet will help to alleviate the symptoms of anaemia.
Thiamine (vitamin B₁), deficiency causes beri-beri.
Riboflavin (vitamin B₂) deficiency causes cheilosis and skin diseases.