Answer:phytoplanktons are photosynthestic organism. They have the ability to produce their own food.
Explanation: Because of there small size they could absorb nutrients in the water even at lower concentration and convert it to energy need for there growth.
Its is said that phytoplanktons are one of the largest producer of oxygen gas.
Answer:
Mutualism
Explanation:
Mutualism: is a relationship between individuals of different species in which both individuals benefit from each other without causing no harm. Example is the nitrogen-fixing bacteria and plants.
One explanation could be the differences in climate (environmental factors). The climate in northern Mexico could support the reproduction of the mosquito species, which is a vector of the dengue virus. Other environmental conditions that influence its endemicity could include living conditions and sanitation. The other possiblity could be that the people in the US have developed immunity for the disease, therefore, are unaffected even when infected by the virus.