AP BIOLOGY

Detailed explanation-1: -Even within each species, individuals look similar to each other but they are not identical. These differences and similarities are because of many small differences between individuals’ genes. All organisms have DNA and each individual’s DNA is organised into genes. These contain the instructions to build our bodies.

Detailed explanation-2: -variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation).

Detailed explanation-3: -All variations in a species do not have equal chances of survival. Some of the variations may be so drastic that the new DNA copy cannot work with the cellular apparatus it inherits. Such, a newborn cell dies soon.

Detailed explanation-4: -The genetic diversity has three different sources: mutation, recombination and immigration of genes. Mutation is the driving force of genetic variation and evolution.