Earth science hope it helps
Answer:
No atoms are created or destroyed in chemical reactions.
Explanation:
Matter cannot be created or destroyed. When two reactants contact each other, a chemical reaction occurs which breaks the bonds between atoms and rearranges them, forming new bonds which transform them into the product. The same amount of atoms exists before and after the reaction.
The genetic variation of organisms has three sources they are mutation, gene flow and sexual reproduction.
Explanation:
Genetic variation are caused by mutation , random mating, random fertilization and recombination between homologous chromosomes during meiosis.
It is a variation in alleles and genes, among the populations. There is a genetic variation within the family of closely- related individuals. If it is a neighborhood there are many families and there is also genetic variation among that group.
An exact genetic copy of the parent organism is produced in asexual reproduction. It only introduces the genetic variation into the population if a random mutation in the organism's DNA is passed on to the offspring.