Competition for food is an example of a biotic factor in an ecosystem. A red squirrel and a grey squirrel living in the same habitat will compete for the same food source. 2. Predator-prey relationships are examples of biotic factors.
Biotic factors are the living parts of the ecosystem, such as plants, animals, insects, fungi and bacteria. Abiotic factors are the non-living parts of the ecosystem, which influence the size and composition of the living parts: these are components like minerals, light, heat, rocks and water.
The molecular clock is a scientific technique which presents a means of estimating evolutionary rates and timescales using genetic data. It uses mutation rate of biomolecules when two or more life forms diverged to estimate the time. Answer is B.
