A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children ($2$ daughters and $5$ sons). Three of the sons suffer from the given disease but none of the daughters are affected which of the following mode of inheritance do you suggest for this disease
Autosomal dominant
Sex-linked dominant
Sex-limited recessive
Sex-linked recessive
A cross involving two different genera is called
Mongolism syndrome is caused by
Mendel enunciated
Disorders of amino acid metabolism results in