Question

Describe briefly:

Geometric growth.

Answer 1

Geometric growth occurs when both progeny cells after mitosis are still able to divide and do so continuously. When grown in a nutrient-rich medium, it happens in many higher plants as well as in unicellular creatures. The lag phase is the period of delayed initial growth caused by the limited initial cell count. Later on, there is exponentially fast expansion. Phase is referred to as a log or exponential.

W₁ = W₀ert

W₁ = final size (weight, height, number, etc.)

W₀ = initial size at the beginning of the period

r = growth rate

t = time of growth

e = base of natural logarithms

r is the relative growth rate and is also the measure of the ability of the plant to produce new plant material, referred to as the efficiency index. Hence, the final size of W₁ depends on the initial size, W₀.

Answer 2

Geometric growth is characterised by slow growth in the initial stages and rapid growth during the later stages. The daughter cells derived from mitosis retain the ability to divide, but slow down because of a limited nutrient supply.