The correct answer is B. A bony skeleton
Explanation:
In biology, Chondrichthyes are mainly marine jawed fishes that have cartilage skeletons rather than bone skeletons and also they have paired fins, this includes animals such as rays and sharks. In terms of origin, it is believed this type of fishes are mainly linked to placoderms that were a type of primitive fish that lived during the Devonian period that had a body skeleton as they were covered by hard structures called plates made of bone. Because of this, it is believed this structures evolved into less rigid ones made of cartilage although both the primitive fish and modern Chondrictyles share features such as the structure of jaws. Therefore, Chondrictyles descended from fishes that had a bony skeleton.
Answer:
According to the cell theory cell is the structural unit of all living organisms and viruses cannot be considered as living organisms according to this theory
Explanation:
Viruses are not made up of cells and they only contain genetic material like RNA or DNA. since viruses are not made up of cells they do no fit the classification of living organisms. To define living organisms other criterion like reproduction, maintenance of homeostasis and ability to adapt to the external environment are mentioned in the cell theory.
Viruses have the ability to replicate and adapt to even extreme conditions of their environment which makes the question of classifying viruses in the category of living organisms even more complicated.
Answer:
B) They are not in the same species.
Explanation:
Cat and dog both are domestic animals but the can not interbreed to produce fertile offspring. Specie is define as those animal which can interbreed to produce fertile offspring so the cat and dog can not interbreed as they belong to two different species. Both species have different <u>chromosome number</u> that's why the can not interbreed. In order to interbreed both the organisms must belong to one specie. E.g As both tiger and lion live in one environment and the interbreed and produce tiglion but it is infertile and can not breed to produce offspring.
You need to test the hypothesis several times and record all results. Once you obtain the same results several times, I think that means its a theory
