Answer: Carbon is the only element that can form so many different compounds because each carbon atom can form four chemical bonds to other atoms
Explanation:
because the carbon atom is just the right, small size to fit in comfortably as parts of very large molecules. Having the atomic number 6, every carbon atom has a total of six electrons.
The correct answer is option A, that is, jaw or jawless fishes.
Agnatha refers to the superclass of jawless fish in the phylum Chordata, subphylum Vertebrata, comprising of both the extinct (conodonts and ostracoderms) and present (cyclostomes) species. It comprises the group of all vertebrates with jaws, that is, gnathostomes.
On the other hand, there are two categories of living fish with jaws. The Osteichthyes (the bony fish) and the Chondrichthyes (the cartilaginous fish). Both the categories of fish comprises of two pairs of lateral fins and a finned tail for impulsion in water.
Answer:
Explanation:
Fish have scales for many reasons. Firstly, to protect the skin of the fish from attacks from predators, parasites and other injuries. Secondly, scales overlap each other in the same way that an armour would protect a person. Hence, providing a layer of protection for the fish.
Answer:
All cells essentially originate from a single fertilized egg.
hope it helps!
Am certain that the factor that prevents us from finding fossils from the Precambian era is that Most rocks from that era are deeply buried. The precambrian is the informal name for the large expanse of time preceding the current Phanerozoic Eon. It began with the Earh's Formation about 4.5 billion years ago and lasted until the advent of multicellular life about 542 million years ago.
