Tag: botany

Quizzes (264) Questions (5276)

Questions Related to botany

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

PS I and PS II occur over

  1. Grana of chloroplast

  2. Matrix of mitochondria

  3. Stroma of chloroplast

  4. Inner membrane of mitochondrion
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The process that converts light energy into chemical energy takes place in a multi-protein complex called a photosystem. Two types of photosystems are embedded in the thylakoid membrane:- photosystem II ( PSII) and photosystem I (PSI). Each photosystem plays a key role in capturing the energy from sunlight by exciting electrons. These energized electrons are transported by “energy carrier” molecules, which power the light-independent reactions.


So, the correct option is 'Option A'.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

How many PGAL molecules would regenerate 15 RuBP

  1. 30

  2. 25

  3. 15

  4. 20.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the Calvin cycle, 6 molecules of PGAL (glyceraldehyde-3-phosphate) are produced per turn equivalent to 3 carbon dioxide molecules fixed. To regenerate 15 molecules of RuBP (which contain 5 carbons each, totaling 75 carbons), 25 PGAL molecules are required.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

Excitation of chlorophyll by light is

  1. Exergonic reaction

  2. Anabolic reaction

  3. Photochemical reaction

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

The first and foremost step of photosynthesis is the excitation of chlorophyll molecule which occurs with the absorption of light. This reaction is photochemical reaction since involves light and results in chemical change by transfer of electrons. The pigments present in the photosystems absorb photon of light. The photons excite electrons in the chlorophyll which then move through the electron transport chain and results in the production of carbohydrates and energy packets NADPH, ATP with the release of oxygen.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

Light reaction of photosynthesis is also called

  1. Calvin cycle

  2. Hill reaction

  3. TCA cycle

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The Hill reaction implies that the light-dependent reaction of photosynthesis is a result of a series of redox reactions and a suitable terminal electron acceptor is required for that reaction to occur. Hence, solar energy is converted to chemical energy by the reduction of NADP to NADPH.


So, the correct option is 'Hill reaction'.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

First reaction in photosynthesis is

  1. Photolysis of water

  2. Excitation of chlorophyll molecules

  3. Formation of ATP
  4. Fixation of CO$ _2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

During the first stage of photosynthesis, called the light-dependent reaction, sunlight excites the electrons in the chlorophyll pigment. The organism uses this energy to create the energy carrier molecules ATP and NADPH, which are crucial for carbon fixing during the second stage.


So, the correct option is 'Excitation of chlorophyll molecules'.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

How much oxygen is formed from 264 g of $CO _2$ and 216 g of $H _2O$?

  1. 96 g

  2. 216 g

  3. 264 g

  4. 192 g.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Moles = Weight in gms/molecular weight
So, moles of CO$ _2$ =264/44 = 6 moles.
  • In same way moles of H2O = 216/18 = 12 moles.
In a reaction of photosynthesis, 6 moles of CO$ _2$ and 6 moles of water lead to the production of 6 moles of oxygen. Here, CO$ _2$ is a limiting reactant. So only 6 moles of oxygen will be formed.So, 6 moles of O$ _2$ = weight in gms/32 (molecular weight of O$ _2$). Weight in gms = 6 x 32 = 192 gms.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

Fluoroscence differs from phosphorescence in being

  1. Delayed emission

  2. Instant emission

  3. Bioluminescence

  4. Chemiluminescence
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Fluorescence is the phenomenon of absorption of energy by molecule or atom and instant emission of a photon of light or electromagnetic radiation after being excited to a higher quantum state. In this, time interval between absorption and emission of energy is very short. Unlike fluorescence, phosphorescence does not show instant emission of radiation. In this, excitation of electrons is accompanied with the change of a spin state. In this, the time interval between absorption and emission of energy is comparatively longer.
Thus, the correct answer is option B.
Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

In plants, food formation during photosynthesis takes place

  1. In root

  2. In leaf

  3. In stem

  4. In flower
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Photosynthesis is the process by which plant utilizes the energy obtained from sunlight to produce glucose from carbon dioxide and water. During this process, oxygen is released as the by product. It takes place in leaf cells. Leaf cells contain chloroplasts. The chloroplasts contain green pigment chlorophyll which prepares the food during photosynthesis.

Thus, the correct answer is 'In leaf'.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

Red drop and Emerson effect have proved the existence of ______________.

  1. Light and dark reactions is photosynthesis

  2. Two distinct photo systems is photosynthesis

  3. The supply of electrons from oxygen evolving complex
  4. Electron transport from water to NDAP$+$ across thylakoids
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

When sun light hits the chloroplast, then

  1. Increase in $pH$ of thylakoid lumen relative to stroma occurs
  2. A measurable decreases in $pH$ in the thylakoid lumen relative to stroma occurs
  3. A measurable decrease in $pH$ in the stroma relative to thylakoid lumen occurs
  4. The $pH$ of both stroma and thylakoid luman becomes equal
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When the light hits the chloroplast, the chemiosmotic potential is established by thylakoid membrane. The carriers in the electron transport chain use some of the electron’s energy to actively transport protons from the stroma to the lumen. During photosynthesis, the lumen becomes acidic, as low as pH 4, compared to pH 8 in the stroma. Therefore answer B is correct.