Answer: The water in the earth is older than earth itself.The water inside earth came out as steam from volcanic vents and the clouds rained down water..Comets also contain lot of water ice.Early period of solar system large amount of comets and asteroids hit the earth They also brought lot of water.
Explanation:
Vertebrates have a bilateral symmetry due to which their entire body is divided into right and left halves while the invertebrates either have radial symmetry or the bilateral symmetry. Therefore, option D is correct.
The other basic differences between the vertebrates and the invertebrates are that vertebrates have a spinal cord and a backbone while invertebrates lack them, vertebrates have well developed brain, lungs or gills in respiratory system and closed circulatory system.
Answer:
Quite literally Everything
Answer:
Yes, you are correct! C,D and E are correct
Answer:
Zooxanthellae only
Explanation:
Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs.
