Which hormone, produced by the alpha cells of the pancreas, raises blood glucose levels? MCQ with Answer and Explanation

Which hormone, produced by the alpha cells of the pancreas, raises blood glucose levels?
A. Insulin
B. Somatostatin
C. Pancreatic polypeptide
D. Glucagon
Answer: Option D
Solution (By JKSSB Mock Tests)
Glucagon is secreted by alpha cells of the islets of Langerhans when blood glucose is low. It acts on the liver to stimulate glycogenolysis (glycogen to glucose) and gluconeogenesis (synthesis of glucose from non-carbohydrates), thereby increasing blood glucose. Insulin, from beta cells, lowers blood glucose. Somatostatin inhibits both.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1
The 'pUC19' plasmid is a widely used cloning vector. A key feature of pUC19 that facilitates the selection of recombinant clones is the presence of:
A. The rop gene for replication control
B. The lacZ gene for alpha-complementation (blue-white screening)
C. Genes for nitrogen fixation
D. Multiple origins of replication

Correct Answer: Option B


Explanation:
pUC19 is a small, high-copy-number cloning vector. A crucial feature for selecting recombinant clones is the presence of the lacZ' gene, which codes for the alpha-peptide of beta-galactosidase. The multiple cloning site (MCS) is located within this lacZ' gene. When foreign DNA is inserted into the MCS, it disrupts the lacZ' gene (insertional inactivation). On media containing X-gal and IPTG, colonies with empty vectors turn blue, while colonies with recombinant plasmids (disrupted lacZ') remain white, allowing easy visual selection.

This question belongs to: Science Biology
Question #2
The type of stem modification found in ginger is:
A. Corm
B. Bulb
C. Tuber
D. Rhizome

Correct Answer: Option D


Explanation:
Ginger is a rhizome, an underground modified stem growing horizontally, bearing nodes, internodes, scale leaves, and buds. Potato is a tuber, gladiolus a corm, onion a bulb (modified stem with fleshy leaf bases). Rhizomes store food and aid vegetative propagation.

This question belongs to: Science Biology
Question #3
In the human body, the 'Blood-Brain Barrier' (BBB) is crucial for protecting the brain. However, in certain areas, the BBB is absent or 'leaky' to allow the brain to monitor the composition of the blood. These areas are called:
A. Thalamic nuclei
B. Circumventricular organs
C. Basal ganglia
D. Corpus callosum

Correct Answer: Option B


Explanation:
While the Blood-Brain Barrier (BBB) protects most of the brain, there are specific areas where the BBB is absent or highly permeable. These are the circumventricular organs (CVOs), which are located around the third and fourth ventricles. Because they lack a typical BBB, they can directly sample the chemical composition of the blood and cerebrospinal fluid. This is essential for their functions, which include neuroendocrine regulation (e.g., the area postrema for vomiting, the organum vasculosum of the lamina terminalis for osmoregulation, and the median eminence for hormone release).

This question belongs to: Science Biology