When blood glucose levels rise, insulin signals cells to take up glucose, removing it from the ...

When blood glucose levels rise, insulin signals cells to take up glucose, removing it from the blood. Diabetes mellitus is a disorder caused by a dysfunction in the insulin signaling system. There are two types of diabetes. People with type 1 diabetes must take insulin regularly, usually through injection. People with type 2 diabetes are not helped by supplemental insulin. What does this tell you about where the defect might be in these two disorders?

a. Type 1 diabetes is probably caused by defective insulin receptors.
b.  Type 2 diabetes is probably caused by a lack of insulin.
c.  Type 2 diabetes is probably due to too much insulin.
d.  Type 1 diabetes is probably caused by a lack of insulin.