One type of natural selection is balancing selection. one scenario that can lead to balancing selection is when a heterozygote phenotype has a fitness advantage. which of the following are reasonable predictions of balancing selection due to heterozygote advantage? assume that after 10 generations under the balancing selection, the f(a1) = 0.5, where "a1" is one of two alleles of a given gene; "a2" is the other allele.

b. the carbon cycle ensures living things have a source of hydrogen

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.