[PEP Edition] Grade 7 Biology (Volume 2): Gateways of Perception

Imagine your body as a highly intelligent control center, with your eyes and ears as its most advanced outposts deployed in the outside world. They are not just physical "lenses" or "resonance chambers," but also incredibly precisebiological transducers. Their core mission is to translate physical energy — light waves and sound waves — into the language the brain understands:nerve impulses.

The Neuroscience of Vision and Hearing

We often say, "The eyes are the windows to the soul." But biologically, the eyes and ears are just "gateways." True perception happens in the cerebral cortex. As shown inthe case study: a woman with perfectly healthy eyes went blind because a brain tumor was compressing her visual center. This tells us that vision is asystematic process.

Scientific Truth: Going Beyond Sensory Limits

The red line illusion above reminds us that our senses have cognitive biases. Scientific research cannot rely solely on "gut feeling" — objective measurement with precise tools like rulers is essential. This shift from "seeing is believing" to "data is the standard" lies at the heart of scientific literacy.

Deep Dive: Cross-System Collaboration

When light signals hit the retina, the regulation of life activities is also activated. This involves not only the rapid response of the nervous system but also the hormonal regulation of the endocrine system (such as adrenaline secretion during fear). The human body is a unified whole.

QUESTION 1

[Fill in the blanks] The logical chain of hearing: From external sound waves to the formation of hearing, the path goes through: external auditory canal → [blank] → auditory ossicles → auditory receptors in the [blank] → [blank] → a specific area of the [blank].

Eardrum; Cochlea; Auditory nerve; Cerebral cortex

Tympanic cavity; Auricle; Spinal cord; Retina

QUESTION 2

[Matching] Based on the two images in the textbook (corneal structure and surgery diagram), which statement about the cornea is INCORRECT?

The cornea is the first transparent gateway for light entering the eyeball

Corneal transplant surgery can restore vision for all blind patients

Corneal disease can prevent light from properly refracting into the eye

QUESTION 3

[Short Answer] Using insulin secretion as an example, what are the secretion characteristics of endocrine glands?

Have ducts; secretions are released through ducts

No ducts; secretions enter the capillaries within the gland directly

QUESTION 4

[Short Answer] A newborn baby will start sucking the first time their lips touch a nipple. Is this a simple reflex or a complex reflex? What is its significance?

Simple reflex; it is an innate instinct that is the foundation for survival

Complex reflex; it is an adaptive behavior acquired through learning

QUESTION 5

[Short Answer] Which of the following practices is correct for eye and ear hygiene?

Using your phone while walking to make the most of your time

Looking into the distance for a few minutes after 1 hour of continuous screen use

Using a sharp ear pick to clean your ears