An organ is the biggest out of all of these. Organs are formed from groups of tissues and tissues are groups of cells. A molecule is one of the small holes you see your hair grow out from.
Answer:
Eukaryotic cells are generally larger and more complex than prokaryotic cells. They also contain a variety of cellular bodies called organelles. The organelles function in the activities of the cell and are compartments for localizing metabolic function.
Explanation:
The heart must beat faster during exersise because by increasing the heart rate the body is able to increase cardiac output and deliver the necessary blood flow to the mucles
Bony fish belong to Class Osteichthyes, while cartilaginous fish belong to Class Chondrichthyes. Bony fish have a bony skeleton, while cartilaginous fish have one composed mostly of cartilage. Bony fish have body coverings of scales, while cartilaginous fish are covered with dendritical projections (think shark skin).
Bony fish are found in fresh and salt water; cartilaginous fish are found only in salt water. Bony fish have gills covered by an operculum; cartilaginous fish have gill slits. Bony have no eyelids; the cartilaginous fish do. Bony fish have an air-filled swim bladder; cartilaginous fish have an oil-filled liver to keep them bouyant. Hope this helps! Whew!