Which type of molecule stores the main source of energy used by animals?
a.) lipids
b.) proteins
c.) glycogen
d.) starch

c.) glycogen

Explanation:

Glycogen is a polysaccharide which is stored as an energy molecule in animals, bacteria and fungi. It is formed by a chain of glucose molecules. The average chain length varies from 8 to 12 glucose units. The glucose units are linked together by α (1-4) glycosidic linkage. The glycogen breaks down into glucose units so as to provide energy to the cells for performing various metabolic functions.  

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.