Which of the following is a type of nekton? shark zooplankton bacteria sea star

shark

Nekton is term which defines pelagic animals that can swim independently in the water currents. It includes three phylla of animals.

1. Vertebrates: These animals exhibit bones and cartilages. This includes species of bony and cartilaginous fishes such as sharks, reptiles like turtles, snakes and crocodiles.

2. Mollusks: This includes squids, octopus and scallops.

3. Crustaceans: This includes shrimps, crabs, and lobsters.

On the basis of above information, shark is the only nekton among the given examples.

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.