__Describe briefly:__

a)Arithematic growth

b)Geometric growth

c)Sigmoid growth curve

Arithmetic growth refers to the situation where a population increases by a constant number of persons (or other objects) in each period being analysed.

Geometric growth refers to the situation where successive changes in a population differ by a constant ratio (as distinct from a constant amount for arithmetic change).

The sigmoid curve is a 'growth average' representing all organisms, where young organisms experience rapid accelerating growth to cope with their environment, followed by a continuous steady growth. Towards maturity, an organisms growth rate slows down until no growth occurs.