When a plant grows toward sunlight it is called positive phototrophism.
A) <u>Mutation</u> is the original source of variations for plants and other organisms which develops differences among their respective species
Explanation:
Genetic variation leads to the natural differences between each individual and among individuals of a species. The main cause for this variation is due to alleles that cause variations in the composition of genes or the DNA sequences.
A mutation is a genetic variation which leads to the creation of a new allele in a species population. Each variation in the DNA sequence leads to an allele formation and each allele leads to a difference in character or trait between individuals since they are the alternate version of the original genes.
Although genetic variations could be brought about by crossing over, random fertilization, or independent assortment; mutation is the original source because it provides the basic raw material for all the evolutionary changes.
The answer is the outer core.
The outer core of the Earth is made up of liquid metal. The liquid in the outer core pass through the magnetic field and this causes the flow of electric current with in it. The magnetic field gets stronger as the liquid metal passes through it. What makes the liquid metal move is the inner core. It heats up the outer core which triggers convection.
