Light can penetrate to only a depth of between 50 and 100 m in most ocean water. what effect does this have on the water's oxygen concentration? explain.

Since light only reaches up to about 50-100 feet underwter, that would mean that plants and bacteria that use sunlight to give off oxygen wouldn't be living in those areas (and deeper), as a result, the oxygen levels would go way down.

Explanation:

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.