Answer:
They are genetically identical to the parents and only differ if a genetic mutation occurs.
Sexual reproduction involves two parents and produces offspring that are genetically unique.
The greater the genetic variation, the better change that an individual in the population have a favorable gene that can help survival. Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population.
Explanation:
Answer: b. Muscles
A metazoa is a division of animal kingdom that includes all animals expect protozoa and sponges. Metazoa division includes multicelluar animals, which exhibit highly differentiated cells. They have muscular and nerve system and well coordinated tissues and organs. Locomotion requires a coordination activity of muscular, skeletal and neural system. It is mainly achieved by contraction and relaxation of muscles that occurs due to specialized muscle proteins named as actin and myosin which receives signals from nerves.
Hence, locomotion in metazoa is due to contraction of muscles.