brodidit for students
Home / Practice / MDCAT / Biology / Support, movement and homeostasis
Support, movement and homeostasis
8 MDCAT Biology questions with answers and explanations.
-
Which tissue joins one bone to another bone?
- 1 Tendon
- 2 Ligament
- 3 Cartilage
- 4 Muscle
Show answer
Correct answer: Ligament
Ligaments connect bone to bone. Tendons connect muscle to bone.
-
Which protein forms the thin filaments of a muscle fibre?
- 1 Myosin
- 2 Actin
- 3 Collagen
- 4 Keratin
Show answer
Correct answer: Actin
Thin filaments are made of actin and thick filaments are made of myosin.
-
Which neurotransmitter is released at the neuromuscular junction?
- 1 Dopamine
- 2 Serotonin
- 3 Acetylcholine
- 4 Adrenaline
Show answer
Correct answer: Acetylcholine
Acetylcholine crosses the junction and makes the muscle fibre contract.
-
Antidiuretic hormone (ADH) causes the collecting duct to:
- 1 Reabsorb more water
- 2 Secrete more water
- 3 Reabsorb less sodium
- 4 Stop filtering blood
Show answer
Correct answer: Reabsorb more water
ADH makes the collecting duct more permeable to water, so more water returns to the blood and the urine is more concentrated.
-
Which part of the brain acts as the body's thermostat?
- 1 Cerebellum
- 2 Hypothalamus
- 3 Medulla
- 4 Pons
Show answer
Correct answer: Hypothalamus
The hypothalamus detects changes in blood temperature and starts responses such as sweating or shivering.
-
The knee is an example of which type of joint?
- 1 Ball and socket
- 2 Pivot
- 3 Hinge
- 4 Gliding
Show answer
Correct answer: Hinge
A hinge joint, like the knee or elbow, allows movement in one plane.
-
Muscle contraction needs ions of which element, released from the sarcoplasmic reticulum?
- 1 Sodium
- 2 Potassium
- 3 Calcium
- 4 Iron
Show answer
Correct answer: Calcium
Calcium ions bind to troponin, which allows actin and myosin to interact.
-
Skeletal muscle fibres are:
- 1 Single-nucleus, smooth and involuntary
- 2 Multinucleate, striated and voluntary
- 3 Branched and striated
- 4 Spindle-shaped and involuntary
Show answer
Correct answer: Multinucleate, striated and voluntary
Skeletal muscle fibres are long, have many nuclei, show stripes under the microscope and are under voluntary control.