Phytoplankton form the base of food webs, but are only present in the upper few hundred meters of the ocean. A number of factors
here can limit their growth and hence limit the amount of biomass in higher trophic levels. Which of the items below is not one of these limiting factors to phytoplankton?
Phytoplanktons are responsible for the fixation of approximately half of the global carbon therefore seawater has high CO2 concentration which is required by phytoplanktons to make their food.
They are the primary producers of oceans and they are responsible to support the food chain of oceans. Factors that can limit their growth are mainly sunlight and nutrients like phosphorus, nitrogen, etc.
As phytoplanktons are photosynthetic they release oxygen itself as a byproduct therefore oxygen is not a limiting factor to phytoplanktons. So the right answer is d.
Antibiotic resistance happens when germs like bacteria and fungi develop the ability to defeat the drugs designed to kill them. That means the germs are not killed and continue to grow. Infections caused by antibiotic-resistant germs are difficult, and sometimes impossible, to treat.
Syphilis is transmitted through sexual actions through small cuts, for malaria, it would have to be through mixing of blood from a contaminated source to a uncontaminated source.
