Answer:
2
Explanation:
you take 1 billion and divide it by 0.5 and to check your work you would take your answer and multiply it by 0.5
The right answer is A. producer.
Phytoplankton are all cyanobacteria and microalgae (microscopic plants) present in surface waters and drifting with the currents. Unknown because invisible to the naked eye, phytoplankton is the lung of our planet. Thanks to photosynthesis, it produces more than half of the Earth's oxygen and consumes half of the carbon dioxide. Phytoplankton is essential for marine life because it is also at the base of the ocean food chain.
I think the answer is skin. Skin contains sweat glands which secrete a fluid waste called sweat or perspiration; nonetheless, its primary functions are temperature control and release of pheromone. Its role as a part of the excretory is therefore minimal. Additionally, sweating also maintains the levels of salt in the body.