In his journey to the Galapagos Islands, Charles Darwin was amazed by the variation in the characteristics of plants and animals he encountered. In any habitat, food can be limited and the types of foods available may vary. One year, there was no rain on these islands. Many plants failed to bloom and produced no new seeds. This left mostly large, tough seeds for the finches to eat. Describe one change in beak characteristics that would most likely occur in the finch population after many generations if this change in seed size became permanent.

the answer would be..

b. sucking

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.