IB DP Biology- D3.3 Homeostasis- IB Style Questions For HL Paper 1A -FA 2025
▶️ Answer/Explanation
✅ Answer: (C) lower — glucagon — liver converts glycogen to glucose
Question
What sequence shows the route taken by nitrogenous wastes in insects from their production in body cells to their removal from the insect’s body?
A. Hemolymph → Malpighian tubule → hindgut → rectum
B. Hindgut → hemolymph → kidney tubule → bladder
C. Malpighian corpuscle → nephron → ureter → bladder
D. Neonicotinoid → rectum → antagonistic muscles → anus
▶️Answer/Explanation
Answer: A. Hemolymph → Malpighian tubule → hindgut → rectum
Explanation:
How do insects excrete nitrogenous waste?
Insects excrete nitrogenous waste (like uric acid) through a specialized excretory system involving Malpighian tubules. These tubules remove waste from the hemolymph (insect blood) and pass it into the hindgut, where water and useful solutes may be reabsorbed. The remaining waste is excreted through the rectum.
Evaluation of Each Option:
A. Correct: Hemolymph → Malpighian tubule → hindgut → rectum
This is the correct pathway for nitrogenous waste in insects. The Malpighian tubules extract waste from hemolymph and deliver it to the hindgut, where final excretion occurs via the rectum.
B. Incorrect: Mentions kidney tubule and bladder, which are vertebrate (human) structures, not found in insects.
C. Incorrect: This option references Malpighian corpuscle, nephron, and ureter, all human/vertebrate kidney structures not relevant to insect excretion.
D. Incorrect: “Neonicotinoid” is a pesticide, not a waste product or anatomical structure. This answer is nonsensical in the context of insect excretion.