List the processes that were mentioned in the reading that contribute to moving carbon through the carbon cycle:
2) Why is this statement false? “The amount of carbon on our entire planet can increase or decrease depending on the fluctuations of the carbon cycle.”
3) What processes are involved in the “short-term” carbon cycles?
4) How does photosynthesis move carbon?
5) What processes are involved in the “long-term” carbon cycles?
6) List some human actions that have been affecting the carbon cycle:
7) Explain how humans, the carbon cycle, and global warming are connected.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

looks like the answer is     c     to me!

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.