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Biology for IGCSE & O level - Plant Nutrition (Section 1)

1
Which process is responsible for the entry of water into guard cells, leading to the opening of stomata?
Answer
(C)
Osmosis
2
What does the diagram of the internal structure of a leaf show?
Answer
(A)
Different tissues, each with important functions to carry out.
3
Where does the light-dependent stage of photosynthesis take place?
Answer
(B)
In the thylakoid membranes of the chloroplast
4
What happens to the rate of photosynthesis if carbon dioxide concentration increases beyond a certain point?
Answer
(C)
The rate plateaus.
5
What is the primary function of the vascular bundles?
Answer
(B)
To transport water and nutrients
6
What is the role of nitrate ions in plants?
Answer
(B)
To make proteins
7
What happens to stomata when the guard cells lose water?
Answer
(B)
They close
8
Which structure is involved in transporting water to the leaves for photosynthesis?
Answer
(A)
Xylem vessels
9
What are the roles of enzymes in photosynthesis?
Answer
(C)
To catalyze the chemical reactions
10
What is the main purpose of the light-independent reactions (Calvin cycle)?
Answer
(C)
To fix carbon dioxide and produce glucose
11
Which of the following structures is responsible for closing the stomata?
Answer
(B)
Guard cells
12
What is the source of energy that drives photosynthesis?
Answer
(B)
Light energy
13
Which of the following is NOT a way that plants use glucose?
Answer
(D)
To make more water
14
What would be the effect on the rate of photosynthesis if the leaves were covered in oil?
Answer
(C)
It would decrease.
15
What is the main function of the leaf's veins?
Answer
(B)
To transport water and nutrients
16
What is the function of the phloem in leaf veins?
Answer
(B)
Transporting sugars
17
What is the role of magnesium ions in plants?
Answer
(C)
To make chlorophyll
18
Why is a large surface area beneficial for leaves?
Answer
(B)
To maximize light absorption
19
In which part of the leaf does the photosynthesis mainly occur?
Answer
(C)
The palisade mesophyll cells
20
Which of the following environmental conditions is most likely to increase the rate of photosynthesis?
Answer
(B)
High light intensity, optimum temperature, high CO2
21
In which part of a plant cell does photosynthesis occur?
Answer
(C)
Chloroplasts
22
What will happen to a leaf if it is deficient in magnesium?
Answer
(C)
It will develop chlorosis
23
What is the role of the spongy mesophyll layer in the leaf?
Answer
(D)
To allow gas exchange through the air spaces
24
What type of tissue in the leaf is responsible for transporting water and minerals?
Answer
(A)
Xylem
25
What type of leaf would be best suited for photosynthesis in an area with high light intensity?
Answer
(C)
A leaf with a thick cuticle
26
What are the products of the light-dependent reactions in photosynthesis?
Answer
A
C
D
27
What type of reaction is photosynthesis?
Answer
(D)
Endothermic
28
What do the guard cells control?
Answer
(C)
The exchange of gases
29
What process is responsible for the release of oxygen during photosynthesis?
Answer
(B)
Splitting of water molecules
30
What does the hydrogen-carbonate indicator solution detect?
Answer
(B)
Carbon dioxide concentration
31
Where does most of the photosynthesis occur in a leaf?
Answer
(C)
In the palisade mesophyll
32
Which of the following is a key function of the cuticle on a leaf?
Answer
(B)
Preventing water loss
33
What is the general relationship between light intensity and the rate of photosynthesis?
Answer
(A)
Directly proportional
34
What is the primary role of the veins in a leaf?
Answer
(B)
To transport water and minerals
35
What happens to the rate of photosynthesis if the amount of water available is reduced?
Answer
(C)
The rate decreases.
36
What is the role of guard cells?
Answer
(A)
To close stomata to prevent water loss
37
What is the role of stomata in plants during the day?
Answer
(C)
To allow carbon dioxide to enter the leaf
38
Which of the following structures facilitates gas exchange in leaves?
Answer
(C)
Stomata
39
What is the primary function of the large surface area of a leaf?
Answer
(B)
To maximize light absorption
40
What is the role of the cuticle on a leaf?
Answer
(B)
To prevent water loss
41
What type of cells would be responsible for the production of a leaf’s waxy cuticle?
Answer
(A)
Upper epidermis cells
42
What would be the appearance of a plant that has a magnesium deficiency?
Answer
(B)
Yellow leaves
43
What is the function of the spongy mesophyll in a leaf?
Answer
(B)
To facilitate gas exchange
44
What is the relationship between the rate of photosynthesis and light intensity?
Answer
(C)
As light intensity increases, the rate increases up to a point.
45
How do plants get the carbon dioxide they need for photosynthesis?
Answer
(B)
From the atmosphere
46
In the diagram of the internal structure of a leaf, which cells are packed tightly together to maximize light absorption?
Answer
(C)
Palisade mesophyll cells
47
What is the main function of the xylem in leaf veins?
Answer
(B)
Transporting water and minerals
48
Which of the following is a reason for plants to produce glucose?
Answer
(A)
To use in respiration
49
What are the reactants in photosynthesis?
Answer
(B)
Carbon dioxide and water
50
Which of the following describes the relationship between light intensity and the rate of photosynthesis?
Answer
(A)
As light intensity decreases, the rate of photosynthesis decreases.