An african american couple is undergoing genetic counseling to determine the likelihood of producing children with a recessively genetic blood condition. the genetic tests reveal that the father carries the trait to produce abnormal hemoglobin, hbs, which causes crystallization in rbcs and deforms their shape when o2 is low. this condition causes painful crises and multiple infarcts and is termed

every el niño cycle is different. every year.

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.