Evolution is a change in the inheritable phenotypic characters within a population occurs through successive generations.
Explanation:
Evolution is a change in inheritable characters of population during a period of time by means of natural selection. These changes in phenotypic characters brings the formation of new species. Darwin's theory consists of three categories,individuals within a group are variables, variations are inheritable,all individuals with variables survive.
According to Darwin's theory states that survival is based on selective mode like particular phenotypic characteristics or behavior given to some individuals who are able to survive in a particular environment.
<span>Answer: Cellular differentiation is responsible for one daughter cell becoming a sieve tube whereas the other becomes a companion cell. Cell differentiation occurs as different genes are switched on and off.
