Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Photosynthesis and Plant Physiology in Detail — 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)
35 × 1 = 35 marks
1.
Photosynthesis takes place inside the cell structure called the:
- A.Nucleus
- B.Chloroplast
- C.Mitochondrion
- D.Vacuole
2.
Chloroplasts appear green because they contain:
- A.Haemoglobin
- B.Chlorophyll
- C.Starch
- D.Water
3.
The thick fluid inside a chloroplast is called the:
- A.Stroma
- B.Granum
- C.Thylakoid
- D.Cytoplasm
4.
A stack of thylakoids is called a:
- A.Stroma
- B.Granum
- C.Membrane
- D.Nucleus
5.
The light reactions of photosynthesis occur in the:
- A.Stroma
- B.Thylakoid membranes
- C.Cell wall
- D.Vacuole
6.
The light reactions of photosynthesis take place in the:
- A.Stroma
- B.Thylakoid membranes
- C.Nucleus
- D.Root
7.
The splitting of water by light energy is called:
- A.Respiration
- B.Photolysis
- C.Transpiration
- D.Fixation
8.
The gas released during the light reactions is:
- A.Carbon dioxide
- B.Oxygen
- C.Nitrogen
- D.Hydrogen
9.
Which two energy-carrying molecules are produced in the light reactions?
- A.ATP and NADPH
- B.Starch and sugar
- C.Water and CO₂
- D.Salt and sugar
10.
Most of the oxygen in Earth's atmosphere comes from:
- A.Volcanoes
- B.Photosynthesis in plants
- C.Burning fuels
- D.Rainfall
11.
The dark reactions of photosynthesis take place in the:
- A.Thylakoid
- B.Stroma
- C.Nucleus
- D.Cell wall
12.
The dark reactions are so called because they:
- A.Happen only at night
- B.Do not need light directly
- C.Need no chloroplast
- D.Make oxygen
13.
The dark reactions take carbon dioxide and carry out:
- A.Photolysis
- B.Carbon dioxide fixation
- C.Transpiration
- D.Respiration
14.
The enzyme that fixes carbon dioxide in the Calvin cycle is:
- A.RuBisCO
- B.Chlorophyll
- C.Amylase
- D.Pepsin
15.
The dark reactions use ATP and NADPH (from the light reactions) to make:
- A.Glucose
- B.Water
- C.Oxygen
- D.Salt
16.
Which of these is NOT a main factor affecting photosynthesis?
- A.Light intensity
- B.CO₂ concentration
- C.Temperature
- D.Soil colour
17.
Increasing light intensity raises the rate of photosynthesis:
- A.Forever
- B.Up to a limit, then it levels off
- C.Only at night
- D.Never
18.
Carbon dioxide is important because it is the raw material for:
- A.The light reactions
- B.The dark reactions (fixation)
- C.Transpiration
- D.Respiration only
19.
Photosynthesis slows in very cold conditions because cold affects the:
- A.Enzymes
- B.Sunlight
- C.Colour of leaves
- D.Roots only
20.
The factor in shortest supply that controls the rate of photosynthesis is the:
- A.Limiting factor
- B.Raw factor
- C.Growth factor
- D.Light factor
21.
The loss of water vapour from the aerial parts of a plant is called:
- A.Respiration
- B.Transpiration
- C.Photosynthesis
- D.Germination
22.
Transpiration occurs mainly through tiny leaf pores called:
- A.Stomata
- B.Roots
- C.Veins
- D.Petals
23.
A stoma is opened and closed by two:
- A.Guard cells
- B.Root hairs
- C.Xylem tubes
- D.Petals
24.
Transpiration generally increases when there is:
- A.High humidity
- B.Strong wind
- C.Total darkness
- D.Cold and calm air
25.
One important benefit of transpiration is that it:
- A.Adds weight to the plant
- B.Helps pull water and minerals upward
- C.Makes food
- D.Stops growth
26.
Water and dissolved minerals are carried in the plant by the:
- A.Phloem
- B.Xylem
- C.Stomata
- D.Cuticle
27.
Food (sugar) made in the leaves is carried by the:
- A.Xylem
- B.Phloem
- C.Root hairs
- D.Guard cells
28.
Water moves up the xylem mainly because of the pull explained by the:
- A.Pressure-flow theory
- B.Cohesion-tension theory
- C.Germination theory
- D.Cell theory
29.
The movement of food through the phloem is called:
- A.Transpiration
- B.Translocation
- C.Respiration
- D.Photolysis
30.
Compared with xylem, the direction of flow in the phloem is:
- A.Always upward only
- B.In different directions (source to sink)
- C.Always downward only
- D.Sideways only
31.
Plant growth regulators are also known as plant:
- A.Hormones
- B.Minerals
- C.Pigments
- D.Enzymes only
32.
Which regulator causes cell elongation and bending toward light?
- A.Auxins
- B.Abscisic acid
- C.Ethylene
- D.Cytokinins
33.
Gibberellins mainly help in stem elongation and:
- A.Closing stomata
- B.Seed germination
- C.Fruit fall
- D.Cell death
34.
The regulator that inhibits growth and closes stomata is:
- A.Auxins
- B.Gibberellins
- C.Abscisic acid
- D.Cytokinins
35.
The hormone that is a gas and promotes the ripening of fruits is:
- A.Ethylene
- B.Auxins
- C.Cytokinins
- D.Gibberellins
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Chloroplast
- (B) Chlorophyll
- (A) Stroma
- (B) Granum
- (B) Thylakoid membranes
- (B) Thylakoid membranes
- (B) Photolysis
- (B) Oxygen
- (A) ATP and NADPH
- (B) Photosynthesis in plants
- (B) Stroma
- (B) Do not need light directly
- (B) Carbon dioxide fixation
- (A) RuBisCO
- (A) Glucose
- (D) Soil colour
- (B) Up to a limit, then it levels off
- (B) The dark reactions (fixation)
- (A) Enzymes
- (A) Limiting factor
- (B) Transpiration
- (A) Stomata
- (A) Guard cells
- (B) Strong wind
- (B) Helps pull water and minerals upward
- (B) Xylem
- (B) Phloem
- (B) Cohesion-tension theory
- (B) Translocation
- (B) In different directions (source to sink)
- (A) Hormones
- (A) Auxins
- (B) Seed germination
- (C) Abscisic acid
- (A) Ethylene
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