Answer:
For calculating the surface to volume ratio for a spherical cell,
Surface area (S) = 4πr²
Volume (V) = 4πr³ / 3
Ratio = S / V = 4πr² / 4πr³ / 3 = 3 × 4πr² / 4πr³
= 3/r
1. 15 micrometer diameter = Ratio = 3/7.5 = 0.4
2. 2 micrometer diameter = Ratio = 3/1 = 3
The cells exhibiting high surface to volume ratio shows enhanced metabolic activity. Shows easy uptake of oxygen, nutrients, water, and also the excretion of waste as they possess large surface.
I haven't done biology in a long time but I am almost certain it is called a acrocentric chromosome.
To act as a catalyst in chem reactions
The traits an organism displays are ultimately determined by the genes it inherited from its parents, in other words by its genotype. Animals have two copies of all their chromosomes, one from each parent.