The primary reservoir of the Mycobacterium responsible for leprosy is:
a. infected humans.
b. infected animals.
c. contaminated food.
d. contaminated objects.
A
The primary reservoir is infected humans. The transmission of leprosy occurs person to person through inhalation or contact with infected skin. It appears that inhalation of M. leprae dis-charged in nasal secretions of an infected individual is the more important mode of transmission.
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What is the function of the temporomandibular joint?
A. It allows the teeth of the upper and lower jaws to fit together precisely. B. It increases the overall strength of the jaws. C. It increases the speed at which the jaws can close. D. It allows the jaw to be more flexible so that large prey items can be consumed. E. It allows the lower jaw to open and close.
Lymph returns to the circulatory system
A. because it is pumped by the heart. B. by entering large veins near the heart. C. by seeping into capillaries. D. when it enters arteries.
What is true of normal human urine production?I-Blood pressure is used to push nitrogenous waste, water, and small molecules through a filter, forming the filtrate, while cells and most proteins are retained in the blood.II-Most water is reabsorbed as the filtrate is passing through a long tube.III-Ammonia is produced as the metabolic breakdown is excreted.
A. just I B. II and III C. I, II, and III D. just II E. I and II
Fatal familial insomnia(FFI) is a very rare prion disease of the brain. FFI has no known cure and involves progressively worsening insomnia, which eventually leads to hallucinations, delirium, and dementia-like symptoms. The average age of diagnosis is about 40 years of age and the average life span after diagnosis is 18 months. FFI is not caused by an infection, but is inherited in an autosomal dominant fashion. Knowing its inheritance pattern AND knowing it is a prion disease, which of the following is accurate?
A. Individuals with FFI have inherited a gene that encodes a mutant form of a prion protein that folds abnormally. B. The abnormal prion protein gradually converts the normal prion proteins of the brain into abnormal prion proteins. C. The abnormal proteins do not get degraded and they form aggregates in brain cells. D. An individual who inherits one copy of the mutant allele will show the FFI phenotype. E. All of these are correct.