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Answer parts (a), (b) and (c) of the question on pages 2–4 of the Section II Writing Booklet - HSC - SSCE Biology - Question 31 - 2013 - Paper 1
Question 31
Answer parts (a), (b) and (c) of the question on pages 2–4 of the Section II Writing Booklet. Start each part of the question on a new page. (a) Outline how the lar... show full transcript
Worked Solution & Example Answer:Answer parts (a), (b) and (c) of the question on pages 2–4 of the Section II Writing Booklet - HSC - SSCE Biology - Question 31 - 2013 - Paper 1
Step 1
Outline how the larynx produces sounds of different frequencies.
Answer
The larynx produces sounds through the vibration of the vocal cords. The tension in the vocal cords is adjustable:
- High frequencies: When the vocal cords are tightly stretched, they vibrate quickly, generating higher-pitched sounds.
- Low frequencies: When relaxed, the vocal cords vibrate more slowly, producing lower-pitched sounds.
The fundamental frequency can also be influenced by the shape and size of the laryngeal cavity.
Step 2
Outline how sound is transmitted to the brain in humans.
Answer
Sound waves travel through the air and enter the ear, causing the eardrum to vibrate. This vibration is transmitted through the ossicles (malleus, incus, and stapes) in the middle ear and into the cochlea in the inner ear.
- Cochlea: Fluid in the cochlea moves, bending hair cells that generate a nerve impulse.
- Auditory Nerve: This impulse travels via the auditory nerve to the brain, where sound is perceived.
Step 3
Describe the process of accommodation. You may include diagrams in your answer.
Answer
Accommodation is the process by which the eye adjusts its focal length to focus on objects at different distances.
- When viewing distant objects, the ciliary muscles relax, causing the lens to flatten and focus light on the retina.
- Conversely, when viewing closer objects, the ciliary muscles contract, allowing the lens to become more rounded, increasing its refractive power.
This adjustment ensures a clear image of the object is formed on the retina.
Step 4
Describe the sequence of events that occurs when photoreceptors in different regions of the retina are stimulated by red light.
Answer
When red light is detected by photoreceptors:
- Photoreceptor cells (mainly cones) in the retina absorb light.
- The absorbed light causes a change in the photopigments within these cells, triggering a chemical cascade.
- This process alters the membrane potential of the photoreceptors, generating an electrical signal.
- The signal is transmitted via bipolar and ganglion cells to form an action potential in the optic nerve.
Step 5
Step 6
Relate your understanding of the use of hearing aids and cochlear implants to possible advantages and limitations of microelectronic chips to vision.
Answer
Hearing aids amplify sound for individuals with hearing loss, while cochlear implants directly stimulate auditory nerves for those with severe hearing impairment.
Microelectronic chips for vision provide limited sight by detecting light, allowing perception of areas of brightness and darkness.
- Advantages: They may assist people in navigating their environment without restoring full vision.
- Limitations: Unlike hearing aids or cochlear implants, these chips do not restore detailed vision or color perception, significantly limiting functional vision.