5a-Reductase catalyzes the metabolism of testosterone to DHT.
Individuals with 5a-reductase deficiency exhibit decreased concentrations of DHT and impaired virilization of the male urogenital tract.
Individuals with 5a-reductase deficiency appear phenotypically female externally or may have ambiguous external genitalia, with normal male internal genitalia.
(E) alpha-Iduronidase (correct)
The only lysosomal storage disease that presents with corneal clouding (as far as I know) is Hurler's syndrome, which is one of two mucopolysaccharidoses, the other being Hunter syndrome. Hunter syndrome can be distinguished from Hurler syndrome in that Hunter syndrome does not present with corneal clouding (Hunters see clearly [no corneal clouding] and aggressively aim for the X [X-linked recessive]). Hurler's syndrome is due to a deficiency in alpha-L-Iduronidase, and Hunter syndrome is due to a deficiency in Iduronate-2-sulfatase. Both diseases lead to an accumulation of heparan and dermatan sulfate.
(C) Cryptosporidium parvum (correct) vs (E) Giardia lamblia (incorrect)
There are three main protozoa that cause GI infections:
(F) Pleural effusion (correct)
Pleural effusion presents with
Note that in pleural effusion, these tests are all "dulled" or are all "decreased".
Pneumothorax presents with
all on the affected side.
Lobar pneumonia (or a consolidated lung) presents with