Difference Between Light and Dark Reactions

Q.

Why do we boil the leaf in alcohol when we are testing it for starch?

Q.

How do you destarch a plant?

1. Place the plant in methylated spirit and heat it over a water bath

2. Place the plant in a dark room for 24-48 hours

3. Place the plant in boiling water

4. Take the plant through the starch test

Q.

Observe the picture below. The variegated leaves are used to determine the role of chlorophyll in photosynthesis. After adding Iodine solution, only green part of leaf show positive result. The possible reason for this is:

Q.

The pigment molecules responsible for photosynthesis are located in the ______.

1. mitochondria

2. cytoplasm of the cell

3. stroma of the chloroplast

4. thylakoid membrane of the chloroplast

Q.

A potted plant was kept in the dark room for 48 hours prior to an experiment on photosynthesis. The purpose of keeping the plant in dark room is:

1. To activate the chloroplast in the plant

2. To activate the enzyme in the leaves

3. To increase the release of O₂.

4. To destarch the plant

Q.

Given below is an incomplete explanation of certain biological processes/terms where a keyword has been left out. Rewrite the completed explanation by inserting the key word in the space indicated by “^”.

Photolysis is the splitting of water molecules into hydrogen ions and hydroxyl ions in the presence of “^”.

Q. Which of the following is the correct sequence of the process of photosynthesis?

1. Splitting of water to H2 and O2 → Absorption of light by Chlorophyll → Reduction of CO2 → Carbohydrate formation
2. Splitting of water to H2 and O2 → Reduction of CO2 → Absorption of light by Chlorophyll → Carbohydrate formation
3. Absorption of light by Chlorophyll → Splitting of water to H2 and O2 → Reduction of CO2 → Carbohydrate formation
4. Absorption of light by Chlorophyll → Reduction of CO2 → Splitting of water to H2 and O2 → Carbohydrate formation

Q. In the experiment of testing co₂ is necessary for photosynthesis what is the need of KOH(pottasium hydroxide).

Q. Arrange the following activities in the order of the speed in which they take place.

(i) Movement of mimosa when it is touched.
(ii) Movement of sunflower in response to day and night.
(iii) Growth-related movements of plants.

1. (ii) – (iii) – (i)
2. (i) – (ii) – (iii)
3. (iii) – (ii) - (i)
4. (iii) – (i) – (ii)

Q.

Which part of pond scum turns blue when treated with iodine?

1. Nucleus

2. Pyrenoid

3. Nucleolus

4. Vacuole

Q. A potted plant was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours. One of the leaves was covered with black paper in the centre. The potted plant was then placed in sunlight for a few hours.
During the starch test why was the leaf -
(1) boiled in water
(2) boiled in methylated spirit.

Q.

Write a balanced equation for photosynthesis.

Q. Following table summarises the differences between light reaction and dark reaction.

	Light reaction	Dark reaction
i	These are also called as biosynthetic phase	These are also called as photochemical phase
ii	These reaction occur over thylakoids.	These reaction occur in stroma of chloroplasts.
iii	These produce assimilatory power i.e.$NADP{H}_2$and ATP	These consume $NADP{H}_2$ and ATP.
iv	These are direction dependent upon light.	These depend upon the products synthesised during light reaction

Which of the above pairs of difference is/are incorrect?

1. (iii) and (iv)
2. (ii) only
3. (i) only
4. (i) and (iv)

Q. A potted plant was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours. One of the leaves was covered with black paper in the centre. The potted plant was then placed in sunlight for a few hours.
Write a balanced chemical equation to represent the process of photosynthesis.

Q. A potted plant was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours. One of the leaves was covered with black paper in the centre. The potted plant was then placed in sunlight for a few hours.
What aspect of photosynthesis was being tested?

Q. Explain about light reaction .

Q. Match column I with column II and select the correct option from the given codes

Sr. no	Column I	Sr.no	Column II
A.	$C_4$ plant	i.	Succulents
B.	Chlorophyll $b$	ii.	Accessory photosynthetic pigment
C.	PS II	iii.	Photooxodation of $H_{2}O$
D.	CAM	iv.	Kranz anatomy

.

1. A - (iv), B - (ii), C - (iii), D - (i)
2. A - (iii), B - (ii), C - (iv), D - (i)
3. A - (i), B - (iii), C - (ii), D - (iv)
4. A - (i), B - (ii), C - (iii), D - (iv)

Q. Differentiate Between.
Action spectrum and absorption spectrum

Q.

1. X-Dark reaction ; Y-Light reaction ; Z-Cytoplasmic inheritance
   
2. X-Light reaction ; Y-Carbohydrate synthesis ; Z-Carbohydrate storage
   
3. X-Light reaction ; Y-Carbohydrate storage ;Z-Carbohydrate synthesis.
4. X-Carbohydrate synthesis; Y- Carbohydrate storage ; Z- Cytoplasmic inheritance
   

Q.

1. $C_6{H}_{12}{O}_6+6O_2\stackrel{Enzymes}{\to }$ $6C{O}_2+6H_{2}O+energy$
2. $C_6{H}_{12}{O}_6+6O_2+6H_{2}O\to 6C{O}_2+12H_{2}O+energy$
3. $6C{O}_2+6H_{2}O\underset{Chlorophyll}{\overset{Sunlight}{\to }}{C}_6{H}_{12}{O}_6+6O_2$
4. $6C{O}_2+12H_{2}O\underset{Chlorophyll}{\overset{Sunlight}{\to }}{C}_6{H}_{12}{O}_6+6O_2+6H_{2}O$

Q. Explain the light reaction and dark reaction of photosynthesis?

Q. Mention one difference between the following on the basis of what is given in brackets.
Light and dark reactions (products formed).

Q.

A potted plant with variegated leaves was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours and then placed in bright sunlight for a few hours. Observe the diagram and answer the questions.​

(ii).Represent the process of photosynthesis in the form of a balanced equation.​

Q. '$C_4$ plants are special.' Comment upon the statement.