The common function of calcium and phosphorus in mammals is that it...

here are the answers to your questions:

1.1.1 The common function of calcium and phosphorus in mammals is that it:
C. prevents rickets.
Both calcium and phosphorus are vital components of bones and teeth, and their deficiency can lead to bone disorders like rickets.

1.1.2 Which of the above are minerals?
C. i, iii, iv
Iron, Sodium, and Potassium are all essential minerals required by the body. Vitamin B is an organic vitamin, and water is a compound.

1.1.3 The process of osmosis may be described as the movement of ...
B. a solvent through a differentially permeable membrane.
Osmosis is specifically the net movement of water (a solvent) across a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration.

1.1.4 The tissue between the upper and lower epidermis in leaves are known as ...
B. mesophyll.
The mesophyll layer, consisting of palisade and spongy mesophyll, is located between the upper and lower epidermis and is the primary site of photosynthesis in a leaf.