Tag: plant nutrition

Questions Related to plant nutrition

Which part of the photosynthetic process does not require light and temperature?

biology plant nutrition limiting factors factors affecting photosynthesis photosynthesis in higher plants

  1. Hill's reaction

  2. Blackman's reaction

  3. Warburg's reaction

  4. Emerson's reaction

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Correct Option: B
Explanation:

The process of carbon assimilation occurs in light independent way. It is called as a dark reaction. Since, Blackman demonstrated the existence of dark reaction, the reaction is also called as Blackman’s reaction.

Thus, the correct answer is option B.

Blackman demonstrated that increasing illumination increased the photosynthetic rate upto a point when $CO _{2}$ become limiting. If light was not limiting, temperature become limiting. Emerson found that maximum $CO _{2}$ fixation could be achieved with brief flashes of light. Choose the correct statement from the following.

biology plant nutrition limiting factors factors affecting photosynthesis photosynthesis in higher plants

  1. Only one factor can be limited in photosynthesis.

  2. Photosynthesis consists of a light and dark reaction.

  3. The trapping of light by chloroplast is temperature dependent.

  4. The trapping of light by chloroplast can occur if $CO _{2}$ is present.

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Correct Option: A
Explanation:

Blackman proposed the law of limiting factors in 1905. According to this law, when a process depends on a number of factors, its rate is limited by the pace of the slowest factor. Blackman's law of limiting factors determines the rate of photosynthesis. Emerson found that maximum $CO _2$ fixation could be achieved with brief flashes of light. From both observations we can say that only one factor can be limiting in photosynthesis at a time. 

The law of limiting factors for photosynthesis was enunciated by

biology plant nutrition limiting factors factors affecting photosynthesis photosynthesis in higher plants

  1. R. Hill

  2. Calvin

  3. Krebs

  4. Blackman

Show answer
Correct Option: D
Explanation:

In the year 1905, Blackman proposed the law of limiting factors for photosynthesis. According to this law the process totally depends upon the light factors and its rate is limited by the pace of the slowest factor. This law of limiting factor determines the rate of the photosynthesis.

so the correct option is D.

Blackman's law of limiting factor is applied to ...........

biology plant nutrition limiting factors factors affecting photosynthesis photosynthesis in higher plants

  1. Respiration

  2. Transpiration

  3. Photorespiration

  4. Photosynthesis

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Correct Option: D
Explanation:

Law of Limiting factor was given by Blackman This law governs the rate of photosynthesis According to this law, the process of photosynthesis is controlled by many factors but the rate of photosynthesis will depend on the factor which is present in limited quantity.

For example, photosynthesis depends upon carbon dioxide concentration, light intensity, water, presence of chlorophyll. If all factors are present but light intensity is low then light will become the limiting factor and rate of photosynthesis will depend only on light, the limiting factor. Hence option D is correct.

Choose the correct answer from the alternatives given.
The rate of photosynthesis declines in the presence of 

biology plant nutrition limiting factors factors affecting photosynthesis photosynthesis in higher plants

  1. Green light

  2. blue light

  3. orange light

  4. far red light

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Correct Option: A
Explanation:
The wavelength of light is also important in the process of photosynthesis. As we know that the  PSI absorbs energy most efficiently at 700 nm and PSII at 680 nm. Light with a higher proportion of the energy of different wavelengths will produce a different rate of photosynthesis i.e the more the wavelength the effective photosynthesis occur. Certain red and blue wavelengths of light are the most effective in photosynthesis because they have exactly the right amount of energy to energize, or excite, chlorophyll electrons. Greenlight is considered the least efficient wavelength in the visible spectrum for photosynthesis, but it is still useful in photosynthesis.
So the correct option is 'Green light'.
The law of limiting factors' was given by _______ in the year _______.
biology plant nutrition limiting factors factors affecting photosynthesis photosynthesis in higher plants

  1. Blackman, 1905

  2. Blackman, 1804

  3. Engelmann, 1909

  4. Warburg, 1920

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Correct Option: A
Explanation:

Blackman's (1905) law of limiting factors states that if a chemical process is affected by more than one factor, then its rate will be determined by the factor which is nearest to its minimal value; it is the factor which directly affects the process if its quantity is changed. 

So the correct option is A.

When the rate of translocation is slow, the rate of photosynthesis shall:

biology plant nutrition experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments

  1. Decrease

  2. Increase

  3. Remain unchanged

  4. Become zero

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Correct Option: A
Explanation:
  • Water in the plant is transported using a pressure flow mechanism. Translocation is the transport of nutrients and carbohydrates from source to sink, which is performed by the phloem. Pholem and xylem are present adjacent to each other in the vascular bundle of the plant. When the sugar ie sucrose is produced in the mesophyll of the leaves is produced it is transferred to the phloem to be transported. As the sugar concentration in the phloem increases water is diffused in the phloem from the xylem and this is what we call ascent of sap. When the water is diffused in the cells due the rigid wall the pressure in the cell increases. due to increase in the pressure at the source and low pressure at the sink the water along with the sugar is transported. As the sugar reaches the sink and leaves the cell water also moves out of the cell. Therefore the rate of photosynthesis is dependent on translocation rate. As the rate of translocation decreases the rate of photosynthesis also decreases.

  • Therefore, option A is correct. 

The process in which liquid water changes into gas is called

botany plant nutrition experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. Precipitation

  2. Condensation

  3. Evaporation

  4. Transpiration

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Correct Option: C
Explanation:

Sun derives the water cycle, heats up water in ocean and seas, and then water vapours evaporate to air. As the vapours move upward the cool temperature there causes it to condense into clouds and they fall as precipitate like rain, hailstone etc.

During photosynthesis, oxygen in glucose comes from

botany plant nutrition experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. oxygen in air

  2. water

  3. carbon dioxide

  4. both (B) and (C).

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Correct Option: B

It is advantageous to use a water plant to demonstrate photosynthesis other than a land plant because

botany plant nutrition experiments on photosynthesis - light importance of light for photosynthesis photosynthesis necessities- experiments various experiments on photosynthesis experiments on photosynthesis - gases

  1. It photosynthesize rapidly

  2. It respires slowly

  3. It does not transpire

  4. O$ _2$ bubbles from cut water plant can be collected over H$ _2 $O

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Correct Option: C