Q4. Assertion: ANF acts as a check on the renin-angiotensin mechanism. Reason: ANF causes vasodilation and so decreases blood pressure. Are both true, and does the reason explain the assertion?
Both are true, and the reason explains the assertion (NCERT Chapter 16, page 212; Chapter 19, page 247).
Q5. How many major peptide hormones does NCERT list for the gastrointestinal tract?
Four: gastrin, secretin, cholecystokinin and gastric inhibitory peptide (NCERT page 247).
Q6. What does gastrin stimulate the gastric glands to secrete?
Hydrochloric acid and pepsinogen (NCERT page 247).