1. Complete the sequence on how we hear sound:
• An object vibrates.
• Air moves in waves.
• Ear flap captures sound.
• Ear drum vibrates.
• Ear bones amplify the vibrations.
• Hairs in cochlea vibrate and send messages to the brain.
2. Loudness of sound is measured in decibels (dB).
3. Sounds louder than 85 dB can be dangerous.
4. Provide two recommendations to protect your ears from loud noises:
• Wear earplugs in loud environments.
• Limit exposure time to loud sounds.
Section 2: The Eye
1. Match the following parts of the eye to their functions:
• Iris: Controls amount of light entering the eye
• Retina: Converts light to nerve impulses (visual transduction)
• Lens: Changes shape to focus light on the retina
• Cornea: Transparent front part of the eye that refracts light
• Ciliary muscles: Adjusts the shape of the lens
2. Short-sightedness occurs when the eye cannot focus on distant objects. It can be
corrected using concave lenses.
3. Long-sightedness occurs when the eye cannot focus on close objects. It can be
corrected using convex lenses.
4. Name two similarities and two differences between an eye and a camera:
• Similarities: Both have lenses that focus light, both capture images
• Differences: The eye adapts to light changes automatically, the camera
requires manual adjustments
Section 3: Circulatory System
1. Define the following terms:
• Arteries: Blood vessels that carry oxygenated blood away from the heart
• Veins: Blood vessels that carry deoxygenated blood to the heart
• Capillaries: Small blood vessels where exchange of substances occurs
between blood and tissues
2. Complete the blanks:
• Arteries have thick walls and carry oxygenated blood away from the heart.
• Veins have thin walls and carry deoxygenated blood to the heart.
• Capillary walls are one cell thick so substances can pass in and out of the blood.
3. Arrange these steps of circulation correctly:
1. Blood picks up oxygen in lungs and releases CO₂ .
2. Oxygenated blood returns to the heart.
3. Oxygenated blood travels to the body.
4. Body cells exchange O₂ for CO₂ .
5. Deoxygenated blood returns to the heart.
6. Blood travels to the lungs.
4. What happens to your pulse rate during exercise, and why?
• Pulse rate change: Increases
• Reason: To supply more oxygen to the muscles and remove CO₂ more
efficiently
5. Describe the structure and function of the heart:
• Structure: Muscular organ with four chambers (two atria and two ventricles)
and valves
• Function: Pumps blood throughout the body to supply oxygen and nutrients
while removing waste