IB DP Biology Mock Exam HL Paper 2 Set 2 - 2025 Syllabus
IB DP Biology Mock Exam HL Paper 2 Set 2
Prepare for the IB DP Biology Exam with our comprehensive IB DP Biology Exam Mock Exam HL Paper 2 Set 2. Test your knowledge and understanding of key concepts with challenging questions covering all essential topics. Identify areas for improvement and boost your confidence for the real exam
Question
The diagram shows a section through part of the leg of an insect and antagonistic muscles X and Y. The tibia moves in the direction shown by the arrow when the muscle is flexing.
(a) Outline a reason for the muscles being described as antagonistic.
(b) Describe the role of muscle Y.
(c) Outline how the muscle attachment of insects differs from humans.
(d) Explain the role of calcium ions in muscle contraction.
Answer/Explanation
Ans:
(a)
cause opposite movements / pull in opposite directions / when one contracts the other relaxes;
(b)
a. flexor/flexion;
b. bends/flexes the leg/limb/joint;
(c)
insect muscle is attached inside (the skeleton) and human muscle outside (the skeleton);
insect muscle is attached to exoskeleton and human to endoskeleton/bones;
(d)
a. calcium released from sarcoplasmic reticulum;
b. calcium binds to troponin;
c. causes tropomyosin to move;
d. uncovers binding sites;