1What is the word equation for photosynthesis?
carbon dioxide + water → glucose + oxygen
2What is the chemical equation for photosynthesis?
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
3Where does photosynthesis occur?
in the chloroplasts of plant cells
4Which pigment is essential for photosynthesis?
chlorophyll
5What are the raw materials needed for photosynthesis?
carbon dioxide and water
6What are the products of photosynthesis?
glucose and oxygen
7What is the main source of energy for photosynthesis?
sunlight
8How does carbon dioxide enter the plant?
through the stomata
9How does water reach the leaves?
via the xylem vessels
10What factors affect the rate of photosynthesis?
light intensity, carbon dioxide concentration, temperature
11What is the effect of increasing light intensity on photosynthesis?
it increases the rate up to a certain point
12Why is photosynthesis important?
it produces oxygen and glucose, which are essential for life
13What is a limiting factor in photosynthesis?
a factor that prevents the rate from increasing beyond a certain point
14What is the glucose produced in photosynthesis used for?
respiration, making cellulose, storing as starch
15How can you test a leaf for starch?
use iodine solution; if starch is present, it turns blue-black
16What must be done to the leaf before testing for starch?
boil it and place it in ethanol to remove chlorophyll
17Why is chlorophyll green?
it reflects green light and absorbs red and blue light
18Why do plants store glucose as starch?
starch is insoluble and doesn't affect water balance
19Which part of the leaf is adapted to absorb light?
the palisade mesophyll layer
20How is the palisade layer adapted for photosynthesis?
it has many chloroplasts and is near the top of the leaf
21How is the spongy mesophyll adapted for gas exchange?
it has air spaces to allow diffusion of gases
22What is the role of guard cells?
they open and close the stomata
23When do stomata usually open?
during the day for gas exchange
24Why do stomata close at night?
to reduce water loss when photosynthesis isn’t occurring
25What is photolysis?
the splitting of water using light energy
26What are the products of photolysis?
oxygen, protons (H⁺), and electrons
27What happens to the oxygen produced in photolysis?
it is released as a by-product
28What is the role of ATP in photosynthesis?
it stores energy for the light-independent reactions
29What are the two stages of photosynthesis?
light-dependent reaction and light-independent reaction
30Where does the light-dependent reaction take place?
in the thylakoid membranes of chloroplasts
31Where does the light-independent reaction take place?
in the stroma of the chloroplast
32What is another name for the light-independent reaction?
the Calvin cycle
33What is carbon fixation?
the process of converting CO₂ into organic compounds
34How does temperature affect photosynthesis?
rate increases with temperature to a point, then enzymes denature
35How does carbon dioxide concentration affect photosynthesis?
increased CO₂ increases rate up to a certain level
36How do you increase the rate of photosynthesis in a greenhouse?
by using artificial light, heaters, and CO₂ generators
37What is a variegated leaf?
a leaf with both green and non-green (white) areas
38Why can’t white areas of a variegated leaf photosynthesise?
they lack chlorophyll
39What is the inverse square law in photosynthesis?
light intensity ∝ 1 / distance²
40Why do farmers use glasshouses?
to control light, temperature, and CO₂ to maximise photosynthesis
41What type of reaction is photosynthesis?
an endothermic reaction
42What does endothermic mean?
a reaction that takes in energy from the surroundings
43What happens to the rate of photosynthesis if temperature is too high?
it decreases due to enzyme denaturation
44How can you measure the rate of photosynthesis?
by counting oxygen bubbles or measuring oxygen volume
45What is a common experiment to investigate photosynthesis?
using pondweed (e.g. Elodea) and measuring oxygen output
46What is the role of magnesium in plants?
to make chlorophyll
47What happens to a plant with magnesium deficiency?
it has yellow leaves due to lack of chlorophyll
48What is the role of nitrate ions in plants?
to make amino acids and proteins
49What happens to a plant with nitrate deficiency?
it shows stunted growth and poor development
50Why are leaves thin?
to allow gases to diffuse quickly
51Why is the upper epidermis transparent?
to let light through to the palisade cells
52Why do leaves have veins?
to transport water (via xylem) and food (via phloem)
53What is transpiration?
the loss of water vapor from the leaves
54What is the relationship between photosynthesis and respiration?
photosynthesis produces glucose for respiration