Tag: botany

Quizzes (264) Questions (5276)

Questions Related to botany

Multiple choice botany water absorption and ascent of sap in plants active transport and passive transport types of plant transport atp

Sucrose moves into sieve tube elements by?

  1. Diffusion

  2. Endosmosis

  3. Active transport

  4. Exosmosis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The mechanism used for the translocation of sugars from source to sink is called the pressure flow hypothesis. As glucose is prepared at the source, it is converted to sucrose. This is moved into the companion cells and then into the living phloem sieve tube cells by active transport. Again active transport is necessary to move the sucrose out of the phloem sap and into the cells which will use the sugar converting it into energy. 


Hence, the correct answer is option C.

Multiple choice botany photosynthesis electron transport system modern concept of photosynthesis photosynthesis in higher plants

Which statement is correct for given reaction for photosynthesis?
$2H _2A+CO _2\overset{light}{\rightarrow}2A+CH _2O+H _2O$.

  1. H donor is oxidisable substrate
  2. $O _2$ evolve from $H _2O$ if reducible compound is $H _2O$
  3. Glucose gain its oxygen from $H _2O$
  4. $(1)$ & $(3)$ both
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the general equation of photosynthesis, H2A represents the hydrogen donor (like water or hydrogen sulfide), which is oxidized during the process.

Multiple choice botany photosynthesis electron transport system modern concept of photosynthesis photosynthesis in higher plants

Find out correct simplified equation of photosynthesis

  1. $\displaystyle CO _2 + 2H _2O \displaystyle

    \overset { light \, energy }{ \underset { chlorophyll }{ \longrightarrow } } C _5H _{10}O _4 + H _2O + O _2 \uparrow$
  2. $\displaystyle CO _2 + 2H _2O \overset { light \, energy }{ \underset { chlorophyll }{ \longrightarrow } } (CH _{2}O) _n + H _2O + O _2 \uparrow$
  3. $\displaystyle CO _2 + 2H _2O \overset { light \, energy }{ \underset { chlorophyll }{ \longrightarrow } } (CH _{2}O) _n + O _2 \uparrow$
  4. $\displaystyle CO _2 + 2H _2O \overset { light \, energy }{ \underset { chlorophyll }{ \longrightarrow } } C _3H _{6}O _3 + CO _2 + O _2 \uparrow$
  5. $\displaystyle CO _2 + 2H _2O \overset { light \, energy }{ \underset { chlorophyll }{ \longrightarrow } } C _6H _{12}O _6 + O _2 \uparrow$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The simplified equation for photosynthesis is CO2 + 2H2O -> (CH2O)n + H2O + O2, where (CH2O)n represents carbohydrates produced.

Multiple choice botany photosynthesis electron transport system modern concept of photosynthesis photosynthesis in higher plants

Splitting of water molecules during light reaction of photosynthesis is associated with
(a) PS I resulting in the release of $O _2$, protons and transfer of electrons to PS II (b) PS II resulting in release of $O _2$, protons and transfer of electrons to PS I (c) PS II resulting in release of $O _2$, protons and transfer of electrons to PS II (d) PS I resulting in the release of $O _2$, protons and transfer of electrons to PS I.
Of the above statements

  1. a alone is correct

  2. b alone is correct

  3. c alone is correct

  4. d alone is correct

  5. b and c are correct.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Photolysis of water occurs at the oxygen-evolving complex associated with Photosystem II, releasing protons and electrons which are then transferred to the electron transport chain.

Multiple choice botany photosynthesis electron transport system modern concept of photosynthesis photosynthesis in higher plants

The source of oxygen evolved during photosynthesis is

  1. $H _2O$
  2. $C _6 H _{12} O _6$
  3. $CO _2$
  4. $n(CH _2O)$.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In the light reaction, the splitting of water occurs. The protons and oxygen formed by splitting of water are released within the lumen of the thylakoid. The oxygen produced is released as one of the net products of photosynthesis.
So, the correct option is 'H$ _2$O' 
Multiple choice botany photosynthesis electron transport system modern concept of photosynthesis photosynthesis in higher plants

During light reaction, as electrons move through photosystems, protons are transported across the membrane. This happens because of __________________.

  1. The primary acceptor of $e^-$(located towards the outer surface of the membrane) transfers its electron not to the $e^-$ carrier but to H carrier
  2. The primary acceptor of $e^-$ transfers only its $e^-$ to $e^-$ carrier.
  3. The primary acceptor of $e^-$ transfers only its $H^+$ to the nearest carrier.

  4. NADP - reductase is present in grana
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

As electrons move through the transport chain, protons are pumped into the thylakoid lumen because the primary electron acceptor transfers electrons to a hydrogen carrier, which then releases protons into the lumen.