Hormones in Animals (Endocrine Glands) MCQs

Q1. Which hormone is secreted into the blood when a person is suddenly frightened or in danger, preparing the body for 'fight or flight'?

• A.Adrenaline
• B.Insulin
• C.Thyroxine
• D.Growth hormone

Answer: A. Adrenaline

Q2. When the hormone adrenaline is secreted into the blood in a frightening situation, which two changes occur in the body?

• A.Increased heart rate and increased blood pressure
• B.Decreased heart rate and decreased blood pressure
• C.Increased appetite and increased thirst
• D.Slower breathing and deep sleep

Answer: A. Increased heart rate and increased blood pressure

Q3. Consider the following statements about hormones in animals: (I) The pituitary is the master gland. (II) Iodine deficiency causes goitre. (III) Insulin is secreted by the adrenal gland. Which of the above statement(s) is/are correct?

• A.Only I and II
• B.Only I
• C.Only III
• D.None of these

Answer: A. Only I and II

To see why, recall that Insulin is secreted by beta-cells of pancreas islets; it lowers blood glucose by promoting uptake into liver / muscle: glucose -> glycogen; deficiency -> diabetes mellitus (high blood sugar) => the stem matches this; hence the answer = Only I and II. That fits the listed correct option directly - Correct. Looking at the others: option B) 'Only I' is wrong because Re-check each statement individually; option C) 'Only III' doesn't hold - Re-check each statement individually. Hence the answer is A) Only I and II.