D is the answer. A gene is a part of a chromosome.
They were imported from China into the United States in 1881.
The first successful release was in Minnesota in 1916.
Hope this helps! :)
Answer: The immune system
Explanation:
The immune system is a complex network of proteins and cells that defends the body against infection or any invasion. The human defense system in the body is actually made up of entire organs and vessel systems like the lymph vessels. The immune system is made up of organs that control the production and maturation of certain defense cells.
Initially, all living things are subjected to attack from disease causing agents. Even bacteria, so small that more than a million could fit on the head of a pin, have systems to defend against infection by viruses. This kind of protection gets more sophisticated as organisms become more complex.
Kingdom Animalia is the kingdom multicellular consumers. Remember that plants are producers mostly, and that Fungi can sometimes be single celled.
