Vidaara.orgClass 11 · Mathematics
CodeVID-M11-WS
Photosynthesis in Higher Plants — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
15 × 1 = 15 marks
1.
Photosynthesis takes place mainly in the:
- A.Mitochondria
- B.Chloroplasts
- C.Nucleus
- D.Ribosomes
2.
The main photosynthetic pigment is:
- A.Chlorophyll a
- B.Carotene
- C.Xanthophyll
- D.Anthocyanin
3.
The light reaction occurs in the:
- A.Stroma
- B.Thylakoid membranes
- C.Cell wall
- D.Vacuole
4.
Splitting of water in the light reaction is called:
- A.Hydrolysis
- B.Photolysis
- C.Glycolysis
- D.Photorespiration
5.
The oxygen released in photosynthesis comes from:
- A.CO₂
- B.Water
- C.Glucose
- D.ATP
6.
The two energy-rich products of the light reaction are:
- A.Glucose and oxygen
- B.ATP and NADPH
- C.CO₂ and water
- D.Starch and protein
7.
The dark reaction (Calvin cycle) occurs in the:
- A.Thylakoid membranes
- B.Stroma
- C.Nucleus
- D.Mitochondria
8.
The CO₂-fixing enzyme of the Calvin cycle is:
- A.RuBisCO
- B.Nitrogenase
- C.Catalase
- D.Lipase
9.
In C3 plants, the first stable product of CO₂ fixation has:
- A.2 carbons
- B.3 carbons
- C.4 carbons
- D.5 carbons
10.
Which of these is a C4 plant?
- A.Wheat
- B.Rice
- C.Maize
- D.Pea
11.
The special leaf anatomy of C4 plants is called:
- A.Kranz anatomy
- B.Dorsiventral anatomy
- C.Isobilateral anatomy
- D.Secondary growth
12.
The wasteful side reaction of RuBisCO largely avoided by C4 plants is:
- A.Photolysis
- B.Photorespiration
- C.Transpiration
- D.Respiration
13.
In nature, the factor that most often limits photosynthesis is:
- A.Carbon dioxide
- B.Oxygen
- C.Nitrogen
- D.Soil colour
14.
According to Blackman's law, the rate is determined by the factor that is:
- A.In shortest supply
- B.In greatest supply
- C.Most colourful
- D.Largest
15.
The rate of photosynthesis falls at very high temperatures because:
- A.Light increases
- B.Enzymes are denatured
- C.CO₂ disappears
- D.Water freezes
Section B — Challenge / Olympiad (2 marks each)
6 × 2 = 12 marks
16.
An experiment using heavy-oxygen-labelled water (H₂¹⁸O) shows the released O₂ is also labelled. This proves the oxygen comes from:
- A.Water
- B.CO₂
- C.Glucose
- D.Chlorophyll
17.
If the light reaction is blocked, the Calvin cycle soon stops because it is deprived of:
- A.ATP and NADPH
- B.Oxygen
- C.Chlorophyll
- D.Water only
18.
On a bright warm day with abundant light and warmth, photosynthesis may still be slow if CO₂ is low. This illustrates that:
- A.The factor in shortest supply limits the rate
- B.Light is always limiting
- C.Temperature is always limiting
- D.Nothing limits the rate
19.
C4 plants such as sugarcane outperform C3 plants in hot climates mainly because they:
- A.Concentrate CO₂ in bundle-sheath cells and avoid photorespiration
- B.Do not need light
- C.Lack chlorophyll
- D.Use no enzymes
20.
Greenhouse growers sometimes pump extra CO₂ into the air because, up to a point, CO₂ is:
- A.A limiting factor that increases the rate when raised
- B.Toxic to plants
- C.Useless to plants
- D.Released, not used
21.
During a drought, photosynthesis slows even in bright light chiefly because water shortage causes:
- A.Stomata to close, cutting CO₂ intake
- B.More chlorophyll to form
- C.The Calvin cycle to speed up
- D.Oxygen to vanish
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Chloroplasts
- (A) Chlorophyll a
- (B) Thylakoid membranes
- (B) Photolysis
- (B) Water
- (B) ATP and NADPH
- (B) Stroma
- (A) RuBisCO
- (B) 3 carbons
- (C) Maize
- (A) Kranz anatomy
- (B) Photorespiration
- (A) Carbon dioxide
- (A) In shortest supply
- (B) Enzymes are denatured
Section B — Challenge / Olympiad (2 marks each)
- (A) Water
- (A) ATP and NADPH
- (A) The factor in shortest supply limits the rate
- (A) Concentrate CO₂ in bundle-sheath cells and avoid photorespiration
- (A) A limiting factor that increases the rate when raised
- (A) Stomata to close, cutting CO₂ intake
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