Answer:
ionic bond
Explanation:
When two ions transfer electrons or bond together they make an ionic bond.
1.Fish gills are organs that allow fish to breathe underwater. Most fish exchange gases like oxygen and carbon dioxide using gills either on side of the pharynx.
2.Gills are branching organs located on the side of fish heads that have many, many small blood vessels called capillaries.
3.The colour is red
4. A Gill filaments project from each arc between the dorsal upper and ventral lower surfaces of the filaments.
The answer is H. He is mechanically digesting his food.
The Drilling sample of the Seafloor spreading theory helped in determining rock ages on the floor of ocean.
Explanation:
The formation of crusts of ocean by the process of volcanic eruptions in the ridges of the middle ocean is the theory of seafloor spreading proposed by Hammond Hess. The movement of tectonic plates continuously forms sea floors through spreading of seafloor. The several evidences in support of this theory has been seen, of which some are – molten material eruptions, magnetic stripes in rocks and rock ages.
The drilling evidence is the final one that was proved by taking samples of rock by drilling in ocean and by bringing them with pipes. The observation of these rocks proved that older rocks were collected from farther ridges and youngers are found in the central ridges.
Natural Selection.
An easy and important way to remember this is by thinking of a species - let’s say a bright white moth. For ages, these moths have survived beautifully, matching perfectly with the white tree bark they live on, until one day, a smoky building begins pumping its soot into the air. This air begins to change the color of the tree bark to black and the once hidden white moths are now plainly visible to birds who eat them easily. Fortunately, every now and then a moth is born who is darker than the rest - black as soot even. And so, the birds keep eating the white moths but missing the soot-colored ones. As time goes by, the soot-colored moths produce more and more similarly colored moths, who are well hidden from the birds AND after enough time, the only moths that remain are soot-colored. This is why so many species “fit” exquisitely into their environment. They have ALL adapted in some way similar to the soot-colored moth.
