Key Concepts in Physics and Biology: Definitions
Key Concepts in Physics
Wave
Wave: A form of energy propagation from one point to another in space, which is not accompanied by a displacement of matter.
Frequency
Frequency: The number of oscillations of a particle per second. Its unit is the Hertz (Hz).
Wavelength
Wavelength: The distance between two peaks. Its unit is the meter (m).
Reflection
Reflection: The change of direction experienced by a ray of light striking the surface of a body.
Refraction
Refraction: The change of direction experienced by a light beam passing from one medium to another in which its speed is different.
Convergent Lens
Convergent Lens: These are thicker in the center than at the sides. They make the light rays concentrate at one point called the focus.
Diverging Lens
Diverging Lenses: They are thicker at the ends than in the middle. They cause light rays to separate.
Intensity
Intensity: The amount of energy that reaches our ear in a unit of time. According to its intensity, sounds may be weak or strong. The intensity is measured in decibels.
Pitch
Pitch: Is determined by its frequency. According to the tone, sounds can be low-pitched or high-pitched.
Timbre
Timbre: The quality that enables us to distinguish sounds of equal intensity and tone produced by different sound sources.
Key Concepts in Biology
Trophic Levels
Trophic levels are the groups of organisms that obtain matter and energy in the same way. They can be:
- Producers: Autotrophic organisms that make their own organic matter from inorganic matter.
- Consumers: Heterotrophic organisms that feed on prepared organic matter.
- Decomposers: Heterotrophic organisms that convert organic matter into inorganic matter.
Myopia
Myopia: The refractive state in which the focus is formed in front of the retina when the eye is at rest, instead of on the retina itself as one would expect. Therefore, it is the reverse of hyperopia, in which the image is formed behind the retina.
Astigmatism
Astigmatism: An eye condition that usually comes from a problem in the curvature of the cornea, preventing clear focus on objects both far and near. When the cornea, normally a spherical surface, undergoes a flattening at the poles, it results in different radii of curvature at the axis of the eye. Thus, when light reaches the eye, specifically in the cornea, the image obtained is unclear and distorted.
Hyperopia
Hyperopia: An eye defect in which the light rays that affect the eye from infinity focus at a point behind the retina, rather than on the retina itself as would be normal. The consequence is that the image is blurred, and there may therefore be a visual acuity deficit.
Marine Zones
Marine Zones:
According to depth:
- Pelagic Zone: The most superficial, reaching 200 m. The area is lit.
- Bathyal Zone: Covers from 200 to 2000 m deep. Swimming animals abound in the light-adapted.
- Abyssal Zone: Below 2000 m. It is characterized by the absence of light and high pressures.
According to distance:
- Neritic Zone: Near the coast, situated on the continental shelf. It is characterized by the continuous movement of water due to swell.
- High Seas Area: Farthest from the coast, downstream of the continental shelf.
Relationships Between Organisms
Relationships Between Organisms:
- Intraspecific: Between individuals of the same species, such as gregarious, colonial, social, or family relations.
- Interspecific: Between individuals of different species.