Tag: biology

Questions Related to biology

What is the primary acceptor of $CO _2$ in Hatch-Slack cycle?

c3, c4 and cam plants photosynthesis in higher plants biology

  1. Phosphoenolpyruvic acid

  2. Ribulose biphosphate

  3. Phosphoglyceric acid

  4. Diphosphoglyceric acid

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Correct Option: A

$C 4$ plants are divided into three subgroups based on ______________.

c3, c4 and cam plants photosynthesis in higher plants biology

  1. Decarboxylation reactions

  2. Oxidation reactions

  3. Reduction reactions

  4. Energy reactions

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Correct Option: A

Which of the following photosynthetic characteristics are present in $C _3$ plants but not in $C _4$ plants?
a. $CO _2$ compensation point of $45$ ppm
b. Relatively higher rate of photo respiratory $CO _2$ evolution
c. Presence of well developed bundle sheath
d. Initial involvement of RuBP carboxyl's(RuBis CO) in $CO _2$ assimilation.
Select the correct answer using the codes given.

c3, c4 and cam plants photosynthesis in higher plants biology

  1. $1, 2$ and $3$

  2. $1, 2$ and $4$

  3. $1, 3$ and $4$

  4. $2$ and $4$

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Correct Option: A

$C _4$ plants are more efficient in photosynthesis than $C _3$ plants because of.

c3, c4 and cam plants photosynthesis in higher plants biology

  1. Higher leaf area

  2. The presence of a large number of chloroplasts

  3. The presence of a thin cuticle on the leaf surface

  4. Lower photorespiration

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Correct Option: A

$C 3$ and $C _4$ and CAM plant species are found in _________.

c3, c4 and cam plants photosynthesis in higher plants biology

  1. Crassulaceae

  2. Cactaceae

  3. Euphorbiaceae

  4. Poaceae

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Correct Option: A

Reductional division involves _________________.

c3, c4 and cam plants photosynthesis in higher plants biology

  1. Separation of non-sister chromatins

  2. Reduction of chromosome number

  3. Separation of sister chromatics

  4. Crossing over

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Correct Option: A

The fixation of $CO 2$ to malate and its decarboxylation are conunon to both $C _4$ and  $CAM$ plants, but in $CAM$ plants these events _____________.

c3, c4 and cam plants photosynthesis in higher plants biology

  1. Are separated spatially

  2. Are separated temporally

  3. Require high light intensity

  4. Require high $CO _2$ concentration

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Correct Option: A

Choose the correct answers from the alternatives given.
Cyanobacteria, unlike other types of bacteria that photosynthesize, do:

c3, c4 and cam plants photosynthesis in higher plants biology

  1. not have a cell wall

  2. not have chlorophyll

  3. give off oxygen

  4. not give off oxygen

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Correct Option: C
Explanation:
Cyanobacteria, also called blue-green algae, were among the earliest organisms on Earth. These primitive bacteria produce oxygen during photosynthesis as they fix CO$ _2$ dissolved in the water. So the correct option is 'Give off oxygen’.

If 24G-3-P molecules are formed in ${ C } _{ 3 }$ plants.Calculate a) the number of $CO _{ 2 }$ used and b) the number of G3P used for regeneration RuBP molecules

c3, c4 and cam plants photosynthesis in higher plants biology

  1. $a=12, b=20$

  2. $a24, b=48$

  3. $a=12, b=24$

  4. $a=20, b=12$

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Correct Option: A
Explanation:

In carbon fixation 5 molecules of C)@ are combines or fixed with 6 molecules; Ribulose Bisphosphate(RuBP) to make 12 molecules of PGA.

The remaining 20 G3P molecules regenerate RuBP, which enables the system to prepare for the carbon fixation step.
So, the correct option is 'a = 12, b = 20'.

Kranz anatomy is not exhibited by which of the following plants?
c3, c4 and cam plants photosynthesis in higher plants biology

  1. Maize

  2. Sorghum

  3. Sugarcane

  4. Sunflower

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Correct Option: D
Explanation:

Kranz anatomy is observed in $C _4$ grasses like Maize, Sorghum and Sugarcane. This is to reduce the inefficiencies of RuBisCO that can catalyse the reaction with $O _2$ rather than $CO _2$ resulting in photorespiration than photosynthesis. To overcome this, $CO _2$ is first as a four carbon compound and then made available to RuBisCO, This is a spatial and temporal separation of reactions into bundle sheath cells and a ring of mesophyll cells surrounding the bundle sheath. Sunflower has only $C _3$ cycle of photosynthesis and does not exhibit Kranz anatomy.

So, the correct answer is 'Sunflower'