Imagine a large source popul ation of 500 flies at a particular time that we will call t0 . the flies have brown or ebony bodies. based on the information given above, how many total alleles for body color exist in the population?

As the population is possessing two phenotypes of the body color, it must then have at least two alleles for the gene of body color. As diploid (2n), each fly exhibits two alleles of the gene for the body color, one allele inherited from the father and one from the mother.  

Therefore, a total number of alleles of the gene for the color of the body in the population is:  

2 × population size, here 2 indicates each fly has two alleles of the gene, that is, 2 × 500 = 1000.  

Hence, the total number of alleles of the stated gene in the population is 1000.  

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.