G10 Effects of Electromagnetic Waves on the Environment Flashcards
is the process by which plants and other photosynthetic organisms (e.g., some bacteria and protists) use energy from sunlight to produce glucose and oxygen gas as by-product
Photosynthesis
sunlight oxygen carbon dioxide sugar water
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starts with the use of light energy. This energy comes in the form of electromagnetic waves.
Photosynthesis
Each particle of light is called a _, each carrying discrete amount of energy
photon
The amount of energy an EM radiation carries depends on its _.
frequency
_ wave carry high amounts of energy while_ waves carry low energy.
High-frequency and low-frequency
energy from light is collected by light-absorbing molecules in the leaves of the plants called
pigments
Pigments can be classified into two groups
hlorophylls and carotenoids
is the most common pigment in plants
Chlorophyll
There are different types of chlorophyll present in a photosynthetic organism.
Photosynthesis happens in a phase called the
light-dependent reaction
when chlorophyll A absorbs light, electrons gain energy and become “excited which results in the splitting of _ molecules
In this reaction, when chlorophyll A absorbs light, electrons gain energy and become “excited which results in the splitting of water molecules and the transfer of energy to _
adenosine triphosphate (ATP)
ATP
adenosine triphosphate
The electromagnetic spectrum is a huge collection of wavelengths of light. Among all these wavelengths, the human eye can only see a portion. This section of the spectrum is called
visible light
This part of the spectrum can be further divided into different subsections, each representative of a particular color, commonly known as the colors of a rainbow
ROYGBV
Objects around us absorb most light rays and also reflect some.
An object’s color is the _ of light which it reflects.
wavelength
The reflected wavelength are received by the _ and _ in the eye interpret these wavelengths as colors and send signals to our brains. This helps us perceive colors and see objects around us.
retina and the cones
Light bounces through objects and enters the eye through the
pupil
is a collection of muscles that contract and expand to regulate light entering the eye
iris
The light then passes through the _, which focuses the light to the _.
lens, retina
is made of a transparent liquid enclosed in a membrane
eye lens
The eye lens is made of a transparent liquid enclosed in a membrane. The thickness of this liquid is adjusted by the _ _ in order to focus on far or nearby objects.
ciliary muscles
The retina contains special cells called _ and _
cones and rods
are responsible for perceiving colors
Cones
allow people to see in poor lighting conditions
rods
is a phenomenon where in short wavelengths of radiation from the sun are absorbed when they pass through a transparent medium while longer wavelengths of radiation are trapped inside that medium
Greenhouse effect
Greenhouse Effect was discovered by
Joseph Fourier in 1824
was built by making a well-insulated box with layers of glass on the lid
A “greenhouse”
The glass allows sunlight to come in, thereby heating the contents of the box. However, the sunlight that enters the greenhouse cannot go out anymore.
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is the most abundant in the atmosphere among all greenhouse gases
Carbon dioxide
is released during the production of energy from fossil fuels.
Methane
is a gas released by various industrial activities. This gas can remain in the atmosphere for thousands of years
Nitrous oxide
is a gas released by various industrial activities. This gas can remain in the atmosphere for thousands of years
Nitrous oxide
in the form of EM waves, reaches Earth atmosphere. Some of these waves are reflected back into space and the rest are absorbed. Thus, heating the lands and the oceans
Solar radiation
Some of this heat is trapped by the greenhouse gases in the atmosphere, thus keeping Earth warm enough to be habitable.
Human activities such as the burning of fossil fuels, car emissions and clearing of forested areas contribute to the increased amount of greenhouse gases in the atmosphere.
is a permanent alteration in the genetic sequence which causes diversity among organisms
Genetic mutation
are changes in the DNA sequence which are inherited by an offspring from a parent
Hereditary or germline mutations
can be caused by factors such as radiation
Acquired or somatic mutations
External influences, such as exposure to specific chemicals or radiation, can cause the DNA to break down. This leads to mutations where cells appear to have a slightly different DNA compared to the original. Cell division causes cells to split up the DNA as new cells are created
is the type of radiation that can knock off an electron from its orbit. This causes direct DNA damage that results in genetic mutations
Ionizing radiation
alpha, beta, and gamma radiation
ionizing radiation
are particles which cannot pass through a piece of paper or the outermost layer of the skin, but if released from inside the body, can do great damage to the cells
Alpha particles
are electrons which can burn the skin since they can penetrate the first layers of the skin
Beta particles
contains huge amounts of energy which can cause a break in the DNA
Gamma radiation
includes ultraviolet (UV) visible light, infrared (IR), microwave, radio frequency (RF), and extremely low frequency (ELF) waves
Nonionizing radiation
In most cases, the skin generally absorbs radiation from nonionizing sources in the form of heat. This is why nonionizing radiation is not that harmful to humans.
is the process that uses electromagnetic waves in the form of light as a source of energy to produce food in plants and photosynthetic organisms.
Photosynthesis
Specifically, light-dependent reactions is a phase in photosynthesis where electrons absorb photons in the form of energy to split water molecules and transfer energy to ATP and NADPH.
are responsible for the absorption of specific wavelength of visible light and reflection of others.
Pigments
The visible light spectrum, composing the colors ROYGBV, is the only EM wave that the human eye can perceive.
Light bounces through objects, enters the eye through the pupil, passes through the lens, and is focused to the retina
Retina contains photoreceptors which are _, responsible for perceiving colors; and, _ which control the light intensity entering the eye
cones,rods
is a phenomenon where longer wavelengths of radiation are trapped inside that medium
Greenhouse effect
contributes primarily to greenhouse effect. Other greenhouse gases include methane, nitrous oxide, fluorinated gases, etc.
Carbon dioxide
Trapped heat by the greenhouse gases in the atmosphere keeps the Earth warm enough to be _.
habitable
There are two types of genetic mutation, germline or somatic. Somatic mutation is caused by factors such as radiation
Ionizing radiation comes from electromagnetic waves with sufficiently high energy that can possibly cause cellular and DNA damage. The most common types of ionizing radiation are alpha, beta, and gamma radiation
_ _ is from electromagnetic waves with relatively low radiation levels believed to be harmless to humans.
Nonionizing radiation
