Tag: energy flow in food chain
Questions Related to energy flow in food chain
One way cycle is
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$CO _{2}$ cycle
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$H _{2}O$ cycle
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Free energy cycle
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$O _{2}$ cycle
Which colour of light is mostly absorbed by chlorophyll a?
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Green
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Yellow
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Blue
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Infra red
Chlorophyll is the pigment responsible for photosynthesis. The light active in photosynthesis is a small part in the visible spectrum (400- 700 nm). The chlorophyll pigments mainly absorb blue and red light. Maximum absorption is in blue light but maximum photosynthesis occurs in red light.
Photosynthesis is most active in
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Sunlight
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Yellow light
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Red light
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Green light
Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. Sunlight comprises all effective lights PAR (photosynthetically active radiations) as required for photosynthesis. Thus, option A is correct.
What is the percentage of photosynthetically active radiation(PAR), in the incident solar radiation.
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100%
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50%
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1 - 5%
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2 - 10%
- Around 50% of the total radiation from sunlight falls under photosynthetically active radiation and supports the process of photosynthesis. It constitutes the light of 400-700 nm wavelength which is absorbed by chlorophyll pigment. Out of which only 2 - 10% are captured by plants. Thus, the correct answer is option B.
Of the total incident solar radiation the proportion of PAR is
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More than 80%
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About 70%
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About 60%
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Less then 50%
Source of energy in an ecosystem is solar energy. 50 per cent of the solar energy incident over Earth is present in PAR (photosynthetically active radiation). Almost 1 to 5 percent of incident solar energy or 2 to 10 percent of PAR is captured by photosynthetic organisms in synthesis of organic matter.
What happens in biological magnification?
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A progressive increase in the level of energy transferred through trophic levels
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A progressive increase in the body weight through trophic levels
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A progressive increase in the number of organisms through trophic levels
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A progressive increase in the amount of harmful substances through trophic levels
Biomagnification (or bioaccumulation) refers to the ability of living organisms to accumulate certain chemicals to a concentration larger than that occurring in their inorganic, non-living environment, or in the case of animals, in the food that they eat. The contaminants include heavy metals namely mercury, arsenic, pesticides such as DDT, and polychlorinated biphenyls (PCBs) compounds which are then taken up by organisms because of the food they consume or the intoxication of their environment. These materials are highly present in a variety of household and industrial chemicals. The harmful substances then build up inside the organism’s cells. When organisms in the higher food chain consume the organisms containing the toxins below their trophic levels, the toxins gradually become concentrated in the higher food chain. Because this is a repetitive process in the ecosystem and throughout the entire food chain, the higher organisms are the ones that will accumulate most of the toxins.
As energy is passed from one trophic level to another, the amount of usable energy
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increases
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decreases
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remains the same
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energy is not passed from one trophical level to another
The total solar radiation proportion of PAR is
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Less than 50%
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More than 80%
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About 70%
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About 60%
Sunlight is like a rain of photons of different frequencies. Visible light consists of radiations having a wavelength of 390-760 nm. Part of spectrum used in photosynthesis has a wavelength of 400-700 nm. It is called photosynthetically active radiation (PAR). The proportion of PAR of the total solar radiation is less than 50%. Only 2-10% of PAR is captured by the plants.
Sun gives radiation in the form of
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Infra-red radiation
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Visible light
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Ultra-violet
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All the above
- Ultraviolet rays: UV rays have a wavelength of 0.01 - 10 nm. These rays can have adverse effects like sunburn, skin cancer if exposure occurs for a long period of time.
- Visible light: Visible spectrum lies in the range of wavelength 400 - 700 nm. These rays are perceived by human eyes. A part of the visible spectrum is used by plants for photosynthesis.
- Infrared rays: These rays have a wavelength beyond the visible spectrum. Most of the radiation emitted from the sun is in the form of infrared radiation.
Which of the following wavelength is absorbed maximum for photosynthesis?
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660 nm
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680 nm
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440 nm
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700 nm
Photosynthesis is the process by which light energy is converted to chemical energy. In plants, light is absorbed by pigments such as chlorophyll. Light hits these molecules and raises them to a higher energy. Light, however, occurs in a spectrum of wavelengths ranging from ultraviolet to visible light to infrared. The energy accompanying the absorption of light is dependent on the wavelength of the light. The amount of energy absorbed during the processes of photosynthesis depends on the wavelength of light absorbed. For processes requiring more energy, pigment molecules must be able to absorb the necessary wavelengths. 680 nm wavelength is absorbed maximum for photosynthesis because, 680 nm will be utilized by both the pigment systems.