Answer:
Division of these two groups occurred after the protostome developmental sequence appeared
The given statement is False.
For a source of water pollution the pollutant can be any undesirable substance present in water.
These undesirable substances can be biological, physical or chemical.
Biological substances such as harmful microorganisms or physical substances such as plastic, garbage and other substances present in water can also be considered as the water pollution.
The chemicals, and other substances are considered as the source of water pollution.
The correct answer is B) chance
Allele frequencies in a gene pool change completely due to chance.