Answer:
a. are probably built by different genes.
Explanation:
Although sharks and dolphins are aquatic animals belonging to the vertebrate group, sharks are fish while dolphins are mammals. Sharks belong to the class Chondrichthyes which are fish that have a cartilaginous skeleton. On the other hand, dolphins are mammals (class Mammalia) which are animals mainly characterized by the presence of mammary glands. In consequence, both species are not closely phylogenetically linked, thereby those genes involved in the development of the integumentary system (skin) in both species are expected to be different.
Nitrogen is needed by organisms to make amino acid which is essential for protein synthesis
Stem cell research has and can lead to medical cures.
Answer:
When fossil fuels are burned, they release toxic gases into the air that cause pollution and increase global warming.
Explanation:
