Which of the following definitions is the best definition of a mutation? A mutation is a permanent change in the order or bases in DNA.
A mutation is a temporary change in the way a cell carries out mitosis.
A mutation is a temporary change in the order of bases in the DNA.
A mutation is a permanent change in the way a cell carries out mitosis.

I think the first answer would be the best option

Explanation:

A mutation is a permanent change in the order or bases in DNA

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.

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.