Question 1
Adult sponges are sessile animals but still show adaptations for movement. What is an example of movement in an adult sponge?
A.
Legs move the body towards food sources
B.
Muscular fins propel the body through water
C.
Cilia generate water currents through the body
D.
Wings lift the body into moving air
Question 2
What is the role of titin in a sarcomere?
A.
It helps the sarcomere recoil after stretching
B.
It forms the smooth surface of joints
C.
It binds calcium to uncover actin sites
D.
It hydrolyses ATP during the power stroke
Question 3
What is a motor unit in skeletal muscle?
A.
One sarcomere and the two Z-discs that bound it
B.
One motor neuron and all the muscle fibres it stimulates
C.
One tendon and all the bones attached to it
D.
One muscle fibre and all the myofibrils inside it
Question 4
In an animal limb, a muscle shortens and pulls on a bone across a joint. What are the lever, fulcrum and effort in this system?
A.
Bone, joint, muscle contraction
B.
Joint, tendon, bone movement
C.
Tendon, ligament, bone contraction
D.
Muscle, cartilage, synovial fluid
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Question 5
What is the correct function of a structure in the human hip joint?
A.
Synovial fluid contracts to move the femur
B.
Cartilage reduces friction between the femur and pelvis
C.
Ligaments attach thigh muscles to the femur
D.
Tendons join the femur directly to the pelvis
Question 6
Male red crabs travel across land during the breeding season to reach areas where mating occurs. What is the main reason for this locomotion?
A.
Foraging for food
B.
Reducing joint friction
C.
Searching for a mate
D.
Escaping from danger
Question 7
A student compares movement in two organisms: the motile unicellular organism Paramecium and an adult sponge fixed to a rocky surface.
Distinguish between movement and locomotion.
[2]
Explain why adaptations for movement can be described as universal in living organisms even though some organisms are sessile.
[2]
Question 8
The diagram shows the human hip joint, a synovial joint.
Name the two bones that form the hip joint.
[2]
Distinguish between the roles of a ligament and a tendon at a synovial joint.
[2]
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Question 9
The diagram shows a dolphin swimming near the water surface.
Outline how streamlining adapts a marine mammal for swimming.
[2]
Explain the functions of the tail fluke and blowhole in a swimming dolphin.
[2]
Question 10
A micrograph of a contracting skeletal muscle fibre shows that the Z-discs move closer together while the darker central band remains the same width. What does this support?
A.
Sarcomeres lengthen as overlap decreases
B.
Actin filaments detach from the Z-discs
C.
Myosin filaments shorten at both ends
D.
Actin and myosin filaments slide past each other
Question 11
A compound prevents ATP from binding to myosin heads in skeletal muscle. What is the immediate effect on the cross-bridge cycle?
A.
Actin filaments actively shorten
B.
Myosin hydrolyses ADP to reset
C.
Myosin remains attached to actin
D.
Tropomyosin exposes actin binding sites
Question 12
A muscle controlling finger movement contains many motor units with few muscle fibres in each unit. What advantage does this arrangement provide?
A.
More precise control of force
B.
Greater friction at each joint
C.
Passive extension without antagonists
D.
Longer sarcomeres in each fibre
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Question 13
A goniometer is used to measure hip flexion. The starting angle is and the final angle is . What is the range of motion?
A.
B.
C.
D.
Question 14
During inhalation, the external intercostal muscles contract. What happens to the internal intercostal muscles at the same time?
A.
They contract to move the ribs up and out
B.
They push the ribs down by active lengthening
C.
They are stretched and store elastic potential energy in titin
D.
They relax because their sarcomeres lose titin
Question 15
What adaptation of whales and dolphins produces most of the thrust during swimming?
A.
Horizontal tail flukes moving up and down
B.
External hind limbs paddling backwards
C.
Vertical tail fins moving side to side
D.
Blowholes pushing water behind the body
Question 16
The diagram shows one sarcomere in a relaxed muscle fibre and the same sarcomere during contraction.
State the change in the position of the Z-discs during contraction.
[1]
Explain why the thick-filament region remains the same length while the sarcomere shortens.
[2]
State the filament that is anchored to the Z-disc.
[1]
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Question 17
During running, a calf muscle is stretched before it contracts to push against the ground.
Outline the role of titin when a sarcomere is stretched.
[2]
Explain why antagonistic muscles are needed to move a joint in opposite directions.
[2]
Question 18
The diagram shows part of a skeletal muscle supplied by one motor neuron. The branches of the neuron end at several muscle fibres.
State the two components that together make up a motor unit.
[2]
Explain how recruitment of more motor units increases the force produced by a skeletal muscle.
[2]
Question 19
A student used a goniometer to measure hip movement. For hip flexion, the starting angle was and the final angle was . For hip rotation, the starting angle was and the final angle was .
Calculate the range of motion for hip flexion.
[1]
State two procedures that improve the reliability or validity of goniometer measurements.
[2]
Suggest why flexion and rotation should be recorded as separate dimensions of hip movement.
[1]
Question 20
The diagram shows the internal and external intercostal muscles between adjacent ribs. The fibres in the two layers have different orientations.
State the effect of contraction of the external intercostal muscles on the ribcage.
[1]
Explain how internal and external intercostal muscles act antagonistically during ventilation.
[3]
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Question 21
Red crabs on Christmas Island move long distances across land to reach coastal breeding areas.
State two reasons for locomotion in animals, other than migration.
[2]
Explain one way in which locomotion can contribute to evolution in a population.
[2]
Question 22
Observations were made on three organisms or life stages. The observations were used to distinguish locomotion from other forms of movement.
Organism / life stage | Observed movement | How it happens |
|---|---|---|
Sponge | Water current passes through body; body remains attached to rock | Beating collar-cell flagella |
Rooted plant | Shoot bends towards light | Unequal cell elongation |
Paramecium | Whole cell swims across slide | Cilia beat |
Identify the organism or life stage in the table that shows locomotion.
[1]
Distinguish between movement and locomotion using evidence from the table.
[2]
Explain why the observations support the statement that adaptations for movement are universal in living organisms.
[1]
Question 23
A human hip joint was examined using an annotated medical image. Several structures at the joint were labelled.
Name the two bones that form the hip joint.
[1]
Distinguish between the roles of a ligament and a tendon at the hip joint.
[2]
Explain how cartilage and synovial fluid facilitate movement at this joint.
[2]
Question 24
A toxin reduces the availability of ATP in skeletal muscle fibres. The toxin does not prevent calcium ions from being released from the sarcoplasmic reticulum.
State the effect of ATP binding to a myosin head during the cross-bridge cycle.
[1]
Explain how ATP hydrolysis contributes to repeated movement of the myosin head.
[2]
Suggest the effect of the toxin on sustained contraction of the muscle fibre.
[1]
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Question 25
The diagram shows a simplified lever system in a vertebrate limb. A muscle attaches close to the joint and pulls on a bone to move a load at the far end of the limb.
Identify the fulcrum and the effort in this lever system.
[2]
Explain one consequence of the muscle attaching close to the joint rather than far from it.
[2]
Question 26
Two skeletal muscles are compared. Muscle X moves the eyeball with fine precision. Muscle Y is a large leg muscle used in jumping.
Predict which muscle is more likely to have smaller motor units. Give a reason for your answer.
[2]
Explain why fibres belonging to different motor units are intermingled within one skeletal muscle rather than arranged in separate blocks.
[2]
Question 27
Electron micrographs of relaxed and contracted skeletal muscle were analysed. Widths of selected sarcomere regions were measured from the same myofibril before and after stimulation.
State the region measured from one Z-disc to the next.
[1]
Describe the change in the light band and the dark band after stimulation.
[2]
Explain how the changes in the graph support the sliding filament model of muscle contraction.
[2]
Question 28
Single muscle fibres from normal mice and mice with reduced titin elasticity were stretched and then released. Sarcomere length was recorded during recovery.
Describe the recovery of sarcomere length after release in the normal fibre compared with the reduced-elasticity fibre.
[1]
Explain how titin contributes to this recovery.
[2]
Suggest one effect of excessive sarcomere stretching on subsequent contraction.
[1]
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Question 29
Motor units were stimulated in two skeletal muscles. Muscle X is used for fine movements and muscle Y is used for powerful movements.
Define a motor unit.
[1]
Using the data, compare the motor units in muscle X and muscle Y.
[2]
Explain why small motor units are suited to fine control.
[1]
Question 30
A goniometer was used to measure the range of motion of the hip joint in several dimensions in two athletes.
Athlete | Movement | Starting angle / | Final angle / |
|---|---|---|---|
Athlete A | Hip flexion | 7 | 122 |
Athlete A | Hip extension | 4 | 28 |
Athlete A | Hip rotation | 9 | 42 |
Athlete B | Hip flexion | 6 | 124 |
Athlete B | Hip extension | 5 | 29 |
Athlete B | Hip rotation | 11 | 45 |
State how range of motion is calculated from the goniometer readings.
[1]
Compare hip flexion with hip rotation using the data.
[2]
Suggest one way to improve the reliability of the measurements.
[1]
Question 31
Radio-tracking was used to study movements of a lizard population over a breeding season. Movement events were classified by behavioural context.
Behavioural context | Observed events / n | Mean distance moved / m | Mean time in exposed habitat / min |
|---|---|---|---|
Foraging for food | 24 | 40 | 12 |
Searching for a mate | 15 | 55 | 15 |
Escaping from danger | 8 | 20 | 3 |
Seasonal relocation | 5 | 450 | 30 |
Identify two reasons for locomotion shown in the stimulus.
[1]
Using the stimulus, outline one cost and one benefit of locomotion.
[2]
Suggest how dispersal by locomotion could contribute to evolution in this population.
[1]
Question 32
Swimming efficiency was compared in three marine mammals with different body shapes and appendage features.
Marine mammal | Body shape | Flippers / tail | Blowhole position | Relative drag / a.u. |
|---|---|---|---|---|
Bottlenose dolphin | streamlined, tapered | pectoral flippers; horizontal tail fluke | on top of head | 1.0 |
Blue whale | streamlined, tapered | pectoral flippers; horizontal tail fluke | on top of head | 1.1 |
Walrus | bulky, rounded | pectoral flippers; hind flippers | none | 2.3 |
Identify one feature in the stimulus that reduces drag in water.
[1]
State the main function of flippers in marine mammals.
[1]
Explain how the tail fluke and blowhole are adaptations for swimming in whales and dolphins.
[2]
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Question 33
Isolated myofibrils were placed in solutions containing different combinations of ATP and calcium ions. Sliding of actin filaments was recorded.
ATP present | present | Sliding distance / m |
|---|---|---|
Yes | Yes | 12 |
Yes | No | 0 |
No | Yes | 0 |
No | No | 0 |
Identify the treatment that would be expected to show the greatest filament sliding distance.
[1]
Explain the role of ATP in the cross-bridge cycle.
[2]
Suggest why many myosin heads remain attached to actin when ATP is absent.
[2]
Question 34
The forelimbs of two animals were modelled as levers. In animal A, the muscle insertion is close to the joint. In animal B, the muscle insertion is farther from the joint.
Identify the fulcrum in the lever model.
[1]
State the role of the skeleton in relation to muscle force.
[1]
Suggest which animal is better adapted for rapid movement of the distal limb, and justify your answer from the stimulus.
[2]
Question 35
Changes in rib position and thoracic volume were recorded during quiet inhalation and forced exhalation. The activity of the external and internal intercostal muscles was also recorded.
Identify which intercostal muscle layer is most active during inhalation.
[1]
Describe the relationship between rib movement and thoracic volume during inhalation.
[2]
Explain how the internal and external intercostal muscles act antagonistically during ventilation.
[2]
Question 36
A motile unicellular organism such as Paramecium caudatum and an adult sponge such as Spongilla lacustris both depend on movement, although only one shows locomotion.
Compare movement and locomotion in the two organisms.
I.
Explain why movement can be considered a universal feature of living organisms.
[2]
II.
Compare the adaptations for movement in a motile unicellular organism and a sessile sponge.
[2]
Discuss why natural selection may favour either locomotion or sessility in different organisms.
[3]
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Question 37
Motor units in two human skeletal muscles were compared. Muscle A moves the eyeball. Muscle B is a large calf muscle used in jumping.
Feature | Muscle A (eyeball) | Muscle B (calf) |
|---|---|---|
Motor unit | 1 motor neuron + its muscle fibres | 1 motor neuron + its muscle fibres |
Muscle fibres controlled by one motor neuron | ||
Motor units in the whole muscle | many | many |
Arrangement of fibres from a motor unit | fibres spread through the muscle and mixed with other units | fibres spread through the muscle and mixed with other units |
Compare the motor units in the two muscles.
I.
Outline the structure of a motor unit.
[2]
II.
Explain why the eyeball muscle is expected to have smaller motor units than the calf muscle.
[2]
Evaluate the advantage of having many motor units with intermingled fibres within one skeletal muscle.
[3]
Question 38
The human hip is a synovial joint formed between the pelvis and femur. It combines stability with a wide range of movement.
Relate the structure of the hip joint to movement.
I.
Explain why the pelvis and femur can act as parts of a lever system.
[2]
II.
Distinguish between the functions of a ligament and a tendon at the hip joint.
[2]
Explain how cartilage, synovial fluid and ligaments contribute to effective movement at the hip.
[4]
Question 39
Marine mammals such as dolphins, seals and whales are mammals adapted for swimming while still breathing air with lungs.
Explain structural adaptations for swimming in marine mammals.
I.
Explain how body shape, flippers and tail flukes improve swimming.
[3]
II.
Contrast the tail movement of marine mammals with that of many fish.
[1]
Discuss how airway adaptations support periodic breathing between dives.
[3]
Question 40
A researcher compared the swimming motions of a dolphin and a bony fish at the same body length. Tail movement and oxygen uptake were measured during steady swimming.
Species | Tail movement | Speed / m s | Oxygen uptake / mL kg min | Thrust / N |
|---|---|---|---|---|
Dolphin | Up and down | 1.0 | 18 | 110 |
Dolphin | Up and down | 2.0 | 30 | 155 |
Dolphin | Up and down | 3.0 | 48 | 200 |
Bony fish | Side to side | 1.0 | 28 | 75 |
Bony fish | Side to side | 2.0 | 47 | 110 |
Bony fish | Side to side | 3.0 | 74 | 140 |
Describe the difference in tail movement between the dolphin and the bony fish shown in the stimulus.
[1]
Explain why up-and-down movement of the tail fluke is consistent with marine mammals having evolved from terrestrial mammals.
[2]
Evaluate the conclusion that the dolphin is better adapted for efficient swimming than the bony fish, using the data and one limitation of the comparison.
[2]
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Question 41
The diagram represents one sarcomere in a relaxed skeletal muscle fibre and the same sarcomere during contraction.
Analyse the structural changes shown in the sarcomere during contraction.
I.
State two changes in the sarcomere that occur during contraction.
[2]
II.
Explain why contraction is described as sliding rather than shortening of filaments.
[2]
Explain how the cross-bridge cycle produces shortening of a myofibril.
[4]
Question 42
A drug being tested on isolated skeletal muscle fibres prevents ATP from binding to myosin after a power stroke has occurred. Calcium ions are still released normally from the sarcoplasmic reticulum.
Predict the molecular effects of the drug.
I.
Explain the state of the actin-myosin cross-bridges after the drug is added.
[2]
II.
Explain why normal calcium ion release would not restore repeated contraction in this situation.
[2]
Evaluate the likely effect of the drug on movement at a joint.
[3]
Question 43
Titin is an immense protein within sarcomeres. Researchers measured passive tension in isolated muscle fibres as the fibres were stretched beyond resting length.
Use the information to explain the role of titin in stretched sarcomeres.
I.
Explain why passive tension increases when a muscle fibre is stretched.
[2]
II.
Suggest why reduced titin elasticity could impair later contraction.
[2]
Explain why antagonistic muscles are needed for relaxation and reversal of movement at a joint.
[3]
Question 44
The forelimb of a vertebrate and the leg of an insect both use muscles and a skeleton to produce movement, but the skeletons are arranged differently.
Explain how skeletons provide anchorage and lever action for muscles.
I.
Distinguish between the anchorage of muscles in arthropods and vertebrates.
[2]
II.
Explain the roles of origin, insertion, fulcrum, effort and load in a limb lever.
[2]
Discuss the mechanical trade-off when muscle effort is applied close to, rather than far from, the fulcrum.
[3]
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Question 45
A sports physiologist compared hip range of motion in several dimensions using video analysis and a goniometer.
Movement | Trial 1 / | Trial 2 / | Trial 3 / |
|---|---|---|---|
Flexion | 118 | 121 | 119 |
Abduction | 42 | 46 | 43 |
Rotation | 31 | 29 | 30 |
Evaluate the measurement of hip range of motion.
I.
Describe how a goniometer should be used to measure an angle at the hip.
[2]
II.
Explain why repeated measurements improve the reliability of range-of-motion data.
[2]
Analyse why the hip can have different ranges of motion in flexion, abduction and rotation.
[3]
Question 46
The external and internal intercostal muscles are skeletal muscles between the ribs. Their fibre orientations differ, allowing them to move the ribcage in opposite directions during ventilation.
Explain how the intercostal muscles act as an antagonistic pair.
I.
Compare the actions of the external and internal intercostal muscles.
[2]
II.
Explain the significance of their different fibre orientations.
[2]
Discuss how this antagonistic action facilitates internal body movement during ventilation.
[3]
Question 47
A population of shore crabs includes individuals that remain near their natal shore and individuals that disperse to other shores before breeding. Researchers recorded survival, feeding success and mating success for both groups.
Trait | Resident crabs / % | Dispersing crabs / % |
|---|---|---|
Survival | 60 | 74 |
Feeding success | 52 | 67 |
Mating success | 45 | 61 |
Analyse the reasons for locomotion shown by the crabs.
I.
Explain two possible benefits of dispersal before breeding.
[2]
II.
Explain three reasons, other than dispersal, why animals use locomotion.
[3]
Evaluate how locomotion and dispersal could contribute to evolution in this population.
[3]
Question 48
During rapid swimming in a young seal, repeated contractions of skeletal muscle move the vertebral column and tail region. A mutation reduces the number of functional neuromuscular junctions in some motor units but does not change the shape of the flippers or tail flukes.
Explain how the mutation could affect contraction from the cellular to the whole-organism level.
I.
Explain the role of a functional neuromuscular junction in initiating contraction of a muscle fibre.
[2]
II.
Explain how fewer functional neuromuscular junctions in a motor unit could reduce swimming performance.
[3]
Evaluate why normal external adaptations for swimming may not compensate fully for the mutation.
[3]
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