MOD 8 Flashcards
Behavioural Adaptation/Example
something an animal does usually in response to some type of external stimulus in order to survive. Hibernating during winter is an example of a behavioural adaptation.
Structural Adaptation/Example
special physical features that make an organism well suited to the environment it lives in. An example is Ducks webbed feet, which are uniquely designed to help them move through the water.
Physiological Adaptation/Example
Internal and/or cellular features of an organism that enable them to survive in their environment. Snakes produce poisonous venom to ward off predators and to capture prey.
Myopia
Short-sightedness (also known as myopia) causes distant objects to appear blurred. In a myopic eye a distant object’s image is formed in front of the retina and not at the retina itself.
Convex Lenses
Convex lenses are used in eyeglasses for correcting farsightedness. Eyeglasses with convex lenses increase refraction, and accordingly reduce the focal length.
Hyperopia
farsightedness is a refractive error that makes nearby objects look blurry. It happens when the shape of the eye makes light focus behind the retina, instead of on it.
Concave Lenses
Placing concave lenses in front of a shortsighted eye reduces the refraction of light and lengthens the focal length so that the image is formed on the retina.
Retina
The retina captures the light that enters your eye and helps translate it into the images you see.
Focal Point
With normal vision, light focuses precisely on the retina at a location called the focal point.
Cochlea
The cochlea is a fluid-filled, spiral-shaped cavity found in the inner ear that plays a vital role in the sense of hearing and participates in the process of auditory transduction. Sound waves are transduced into electrical impulses that the brain can interpret as individual sound frequencies.
Cochlear Implant
A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin (see figure).
Homeostasis
A self-regulating process by which a living organism can maintain internal stability while adjusting to changing external conditions.
Negative Feedback Loop
The hallmark of a negative feedback loop is that it counteracts a change, bringing the value of a parameter—such as temperature or blood sugar—back towards it set point.
Glucose Feedback Loop
If the blood glucose level is too low, the pancreas releases the hormone glucagon. This travels to the liver in the blood and causes the break-down of glycogen into glucose. The glucose enters the blood stream and glucose levels increase back to normal.
Temperature Feedback Loop
If the temperature is high, the body sweats in order to cool down by dilating blood vessels. If the temperature is low, the body shivers by constricting the blood vessels to conserve the heat as the body’s movement generates it.
