biology

2. The powerhouse of the cell
5. A messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system
7. The classical doctrine of the nervous system determines that it is a highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body.
8. A passive biological system that removes excess, unnecessary materials from the body fluids of an organism.
9. Consists of the gastrointestinal tract plus the accessory organs of digestion.
10. The basic building blocks of all living things.

1. the system that circulates blood and lymph through the body, consisting of the heart, blood vessels, blood, lymph, and the lymphatic vessels and glands.
2. Organ system consisting of skeletal, smooth, and cardiac muscle. It permits movement of the body, maintains posture, and circulates blood throughout the body.
3. Polymer composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses.
4. A complex network of cells, tissues, organs, and the substances they make that helps the body fight infections and other diseases.
6. the set of organs forming the outermost layer of an animal's body. It comprises the skin and its appendages, acting as a physical barrier between the external environment and the internal environment that it serves to protect and maintain the body of the animal.