Answer: Sea stars move using a water vascular system. Water comes into the system via the madreporite. It is then circulated from the stone canal to the ring canal and into the radial canals.
Explanation: The radial canals carry water to the ampullae and provide suction to the tube feet.
Recessive genetic disorders result from inheriting 2 defective recessive alleles of gene ( one from each parent ). The x - chromosome holds about 10% of all human genes. Sex chromosomes are: males XY, females XX. Y-traits occure in males only. Y-disorders are rare.
Answer: Most recessive disorders are on the Autosomal recessive gene, and thus not x-linked.
An antigen is recognized by lymphocytes to be foreign and causes an immune response. It is important to know about the immune system of the body as well. The immune system is the system that recognizes and defends itself against any viruses, bacteria or any other harmful foreign bodies.
