Tag: photosynthesis in higher plants

Questions Related to photosynthesis in higher plants

State whether the following statements are true or false.
Oxygen liberation is absent in bacterial photosynthesis.

c3, c4 and cam plants photosynthesis in higher plants biology

  1. True

  2. False

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Correct Option: A
Explanation:

Oxygen liberation is absent in bacterial photosynthesis as they have pigment bacteriochlorophyll for photosynthesis and this pigment does not work in the presence of oxygen. Cyanobacteria are the only bacteria which performs oxygenic photosynthesis. 

So, the correct option is 'True'.

Choose the correct answer from the alternatives given.
Carbon becomes available to crop plants in the form of:

c3, c4 and cam plants photosynthesis in higher plants biology

  1. elemental carbon

  2. carbonates

  3. carbon dioxide

  4. carbohydrates

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Correct Option: C
Explanation:

Plants use carbon dioxide during photosynthesis, the process whereby the plant converts the energy from the sun into a chemical carbohydrate molecule.

So the correct answer is "carbon dioxide".

Photosynthesis in C$ _4$ plants is relatively less limited by atmospheric C$O _2$ levels because 

c3, c4 and cam plants photosynthesis in higher plants biology

  1. effective pumping of CO2 into bundle sheath calls

  2. RuBisCo in C4 plants has higher affinity for CO2

  3. four carbon acids are the initial CO2 fixation products

  4. the primary fixation of CO2 is mediated via PEP carboxylase.

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Correct Option: D
Explanation:

Plants such as sugarcane and sorghum fix atmospheric carbon dioxide into phosphoenol pyruvic acid to produce oxaloacetic acid( a C$ _4$ acid) in the presence of phosphoenol pyruvate carbooxylase(PEP carboxylase). Such plants are called C$ _4$ plants.

In C$ _4$ plants, the primary product of OAA is mediated by PEP carboxylase, so it is relatively less limited by atmospheric CO$ _2$ levels.

So, the correct answer is 'The primary fixation of CO$ _2$ is mediated via PEP carboxylase'.

...............fixes carbon in green plants as simple sugars

c3, c4 and cam plants photosynthesis in higher plants biology

  1. Denitrification

  2. Photosynthesis

  3. Carbonation

  4. Bacteria.

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Correct Option: B
Explanation:

Photosynthesis is a process that converts $CO _2$ into organic compounds and starch (carbohydrate) using energy from sunlight. $O _2$ is also released during this process.

The saturation point of $CO _2$ in $C _4$ plants is?

c3, c4 and cam plants photosynthesis in higher plants biology

  1. $390$ $\mu l/L$

  2. $450$ $\mu l/L$

  3. $460$ $\mu l/L$

  4. $360$ $\mu l/L$

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Correct Option: D

Calculate the death rate if $6$ individuals in a lab population of $60$ fruit flies died during a particular week?

c3, c4 and cam plants photosynthesis in higher plants biology

  1. $0.2$

  2. $0.1$

  3. $1$

  4. $5$

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Correct Option: A

Opening and closing of stomata is controlled by

blackman's principle of limiting factors photosynthesis in higher plants biology

  1. $K^{+}$

  2. $Mg^{2+}$

  3. $Ca^{2+}$

  4. None of the above

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Correct Option: A
Explanation:

Potassium ions are involved in turgor movement of guard cells. Formation of organic acids like malic acid in guard cells promotes intake of potassium into the guard cells, which causes a decrease in water potential leading to intake of water by guard cells.

Among these groups, one element is involved in opening and closing of stomata, the other helps to maintain ribosome structure. Choose the correct option.

blackman's principle of limiting factors photosynthesis in higher plants biology

  1. K and Ca

  2. P and S

  3. K and Mg

  4. Fe and Mg

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Correct Option: C
Explanation:

Potassium (K) and Magnesium (Mg) are essential macronutrients for plants.

K is absorbed as $K^+$. In plants, it is required in more abundant quantities in the meristematic tissues, buds, leaves and root tips. It helps to maintain an anion-cation balance in cells. It is involved in opening and closing of stomata.
Mg is absorbed by plants in the form of divalent magnesium ion ($Mg^{2+}$). It is required in the growing area of roots and stem, seeds, leaves, etc. It occurs as magnesium pectate in middle lamella. It is responsible for maintenance of ribosome structure because it is required for the binding of ribosome subunits during protein synthesis

Which process is responsible for controlling the movement of guard cells? 

blackman's principle of limiting factors photosynthesis in higher plants biology

  1. Transpiration

  2. Photosynthesis

  3. Osmosis

  4. Diffusion

Show answer
Correct Option: C
Explanation:

Osmosis is the process which regulates the opening and closing of stomata by guard cells. When potassium ions accumulate in the cells, the water potential drops and endosmosis occurs making the cell turgid. This causes the cells to take a shape so that the stomatal pore is opened up. When water moves out of the cells, the cells become flaccid and the pore closes.

So, the correct answer is 'Osmosis'.

According to modern theory of stomatal opening, proposed by Levitt, $pH$ of guard cell can rise due to 

blackman's principle of limiting factors photosynthesis in higher plants biology

  1. $CO _2$ assimilation by guard cells only

  2. Active eflux of $H^+$ ion by guard cell

  3. Conversion of starch into PEP

  4. Active uptake of $K^+$ in guard cell

Show answer
Correct Option: A
Explanation:

Modern theory of stomatal movement is proposed by Levitt. According to it, entry of K+ ions leads to the opening of stomata during day time and exist of k+ results the closure of stomata during night time. Simultaneously, carbon dioxide assimilation occur during day time in the guard cells.

So, the correct option is ‘CO2 assimilation by guard cells only’.