Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?

Calculate the oxygen requirement for the removal of organic pollutants.

How does cell division help in the formation of unicellular and highly evolved multicellular organisms like human being?

Give reasons as to why cell division can or cannot be a type of reproduction in multicellular organisms.

Which division is necessary to maintain constant chromosome number in all body cell of multicellular organism and why ?

The amount of oxygen required to oxidies organic substance present in water is called

The amount of oxygen required to oxidise organic substance present in water is called

Do cells of alveoli or lungs also require oxygen to carry out cellular respiration ? Why / Why not ?

In the pond , we find that different organisms live in different regions. This is due to some conditions like availability of different amount of food, air, light etc. Now let us study the table 4 , showing organisms living in different regions of a pond and answer the question. Are the leaves of all plants growing in a pond, similar? What is the difference between the leaves of a plant growing at the bottom (hydrilla) and.that floating on the surface (lotus)? Try to think and write why we find such differences.