Which of the following does not involve a bacterial exotoxin?
diphtheria
whooping cough
scarlet fever
q fever

Option D. "Q fever"

Explanation:

Q fever, the zoonotic disease is caused by a bacteria rickettsia, Coxiella burnetii. The major cause of this bacterial disease is domestic livestock such as, sheep, goats and cattle.

In humans, the primary route of Q fever is through inhalation of contaminated farmyard aerosols. Symptoms with acute Q fever involves pneumonia, high fever, coughing, headache, and general malaise.

Hence, the correct option is D.

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.