The Islets of Langerhans are:

Diabetic patients are successfully treated by

Diabetes mellitus is due to the lack of:

Which hormone's presence is necessary in the target cells for glycogenesis?

Which of the following is the function of Insulin?

$A$ sample of urine was diagnosed to contain a high content of glucose and ketone bodies. Based on this observation, answer the following:
$(a)$ Which endocrine gland and hormone is related to this condition?
$(b)$ Name the cells on which this hormone acts.
$(c)$ What is the condition called and how can it be rectified?