The answer is litter carbon dioxide bubbles
I hope that helped
B. Gene expression is in them is similar to us but facilitates the use of bacteria in recombiant biotechnology and gene therapy.
We human have eukaryotic cells which have a devoloped nucleas whereas small bacteria have prokaryotic cells with no definite nucleus using more biotechnology. Other all are not true.
The correct answer is - Most killer whales congregate in the areas that are near the Arctic/Antarctic Circles.
The killer whales have a very large distribution, and they can be found in all oceans, apart from the Southern Ocean. It is noted though that the population density of the killer whales differs from place to place. The higher concentrations are found around the Arctic and Antarctic Circles, where there's cool rich waters, while in the lower latitudes they are much rarer. The reason for this probably lies in the fact that most of the animals that are considered to be the prime food source of the killer whales are living in this rich cold waters.