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!
Answer:
A. lack both antigens A and B on their erythrocytes.
Explanation:
A person with blood type O would lack both antigens A and B on their erythrocytes.
Answer:
It could lead to several later problems in the cell.
Explanation:
Removing a piece of DNA could severely affect the cell but it could also cause nothing. Depending on the part that is damaged, it could codify for a vital protein but it could also be an intron, which are pieces of DNA that don't codify for any protein. This has been recently researched and even though there are introns that could cause some serious trouble, most of them are an unknown matter to nowadays scientists. Anyway, a wrongly repaired sequence could end in a mutation that can potentially damage the cell and therefore the organism.
