How are biotic factors in the marine ecosystem responsible for bringing carbon-dioxide into the ocean?

Marine ecosystem have biotic organisms like phytoplankton and photosynthetic algae that do photosynthesis and converts the atmospheric carbon dioxide into organic matter most of the carbon dioxide is released when other organisms eat phytoplankton and release the carbon dioxide through respiration.

But some of the algae and phytoplanktons die naturally get down to the bottom of the ocean where they make carbon sink. Some organisms accumulate CO₂ in their exoskeleton that is made up of calcium carbonate.  

Therefore this use of carbon by living organisms in oceans brings carbon dioxide from the atmosphere to oceans. This is why the ocean plays a critical role in the carbon cycle and called carbon sink.

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.

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.