Target: 10 questions in 10 minutes
1. Which of the following best explains why animals engage in locomotion?
  • A. To maintain body temperature
  • B. To migrate
  • C. To excrete waste products
  • D. To communicate with other species

Q2&3. The image shows a frontal view of a human hip joint:

human hip joint - diagram

 DataBase Center for Life Science (DBCLS)
CC-BY-SA 4.0
2. Which structure acts as a muscle attachment point and lever?
3. Which letter is best described as a non-elastic structure for bone to bone joining?
4. What is the primary function of titin in muscle contraction and relaxation?
  • A. To slide over actin and shorten sarcomere
  • B. To store energy for muscle contractions
  • C. To transport calcium ions
  • D. To prevent overstretching and help sarcomeres recoil

5. What adaptation(s) is/are observed in marine mammals for swimming?

I. Streamlining of the body shape to reduce drag
II. Adaptation of pentadactyl limbs to form flippers
III. Adaptation of limbs to form a fluke for up-and-down movement
IV. Changes to the airways to allow periodic breathing between dives
  • A. I and III only
  • B. I and IV only
  • C. II and III only
  • D. I, II, and IV

6. Following depolarisation at the neuromuscular junction, what is the correct order to describe muscle contraction by the sliding filament theory?

I. Cross-bridge formation
II. Calcium ion release
III. Sarcomere shortening
IV. Sliding of actin and myosin filaments
  • A. I → II → IV → III
  • B. IV → II → I → III
  • C. II → I → IV → III
  • D. I → II → III → IV
7. What is the role of calcium ions in the sliding filament theory of muscle contraction?
  • A. Calcium ions form a cross-bridge with actin filaments
  • B. Calcium ions trigger repolarization within the sarcolemma
  • C. Calcium ions bind to troponin helping to expose myosin binding sites on actin
  • D. Calcium ions release stores of ATP, providing energy for muscle contraction

Q8-10. The diagram below shows an electron micrograph of a single sarcomere.

human hip joint - diagram

 Bjecas (adapted)
CC-BY-SA 3.0
8. Which label best corresponds to the sarcolemma?
  • A. R-S
  • B. R-Q
  • C. X-Y
  • D. None of these
9. Which label best corresponds to the myosin fibres?
  • A. R-S
  • B. R-Q
  • C. X-Y
  • D. None of these

10. How would the lengths of R-S, R-Q and X-Y change when the sarcomere relaxes?

  R-S  R-Q X-Y
A Longer No change No change 
B Longer Longer No change
C Shorter No change Longer
D Longer No change  Longer