Leaving Certificate Photosynthesis Practice Test

These questions are part of the practice quiz. Start practicing

• What is the main source of energy for photosynthesis?
• Describe the significance of RuBP regeneration in the Calvin cycle?
• Which statement best contrasts C3 and C4 photosynthesis regarding CO2 concentration and typical habitats?
• Name the cells that control the opening of the stomata.
• The energy used in photosynthesis is captured from which form of energy?
• Describe CAM photosynthesis and its adaptation.
• What is the primary function of RuBisCO in the Calvin cycle?
• In C4 plants, what is the sequence of CO2 fixation and release?
• Name the element at the centre of a chlorophyll molecule.
• The dark stage is also known as which of the following?
• Which organisms perform oxygenic photosynthesis?
• What does the thylakoid membrane house during photosynthesis?
• What supplies energy for carbohydrate synthesis in the dark stage?
• Which complex is responsible for splitting water to release oxygen in photosynthesis?
• Where do the light-dependent reactions occur?
• Which enzyme catalyzes the initial CO2 fixation in C4 plants?
• Which tissue transports water from roots to leaves?
• What is the main carbohydrate produced during photosynthesis?
• For a pondweed experiment, how would you quantify the rate of photosynthesis?
• Name the two types of particle transferred from NADPH to CO2 in the dark stage of photosynthesis.
• What is photorespiration and under what conditions does it occur?
• What is the difference between oxygenic and anoxygenic photosynthesis?
• Which enzyme catalyses the first CO2 fixation in the Calvin cycle and why is its activity significant?
• In leaf cells, which pigment traps light energy for photosynthesis?
• How does light intensity affect the rate of photosynthesis?
• What is Hill's reaction and its purpose?
• What happens to ADP and NADP+ at the end of the dark stage of photosynthesis?
• What happens to the oxygen released from splitting water?
• What substance is split into electrons, oxygen and protons during photosynthesis?
• In which pathway of the light stage is oxygen produced?
• In which stage of photosynthesis is oxygen produced?
• Which organelle carries out photosynthesis in plants?
• Where does the water needed for photosynthesis enter the plant?
• What is the primary product of the Calvin cycle used for sugar synthesis?
• Which is a fate of oxygen after production in photosynthesis?
• What happens to the hydrogen released when water is split?
• Besides carbon dioxide, which small molecule is needed for photosynthesis?
• How does CAM photosynthesis differ from C4 in terms of stomatal behavior and timing?
• Why are ATP and NADPH production during the light reactions essential for the Calvin cycle?
• Suggest a reason why life on earth might not continue without photosynthesis.
• Where do ADP and NADP+ go after the dark stage?
• What is the electron donor for PSII and the key process at PSII?
• What is the role of the chloroplast envelope?
• How is NADPH formed in the light-dependent reactions of photosynthesis?
• Which is true about CO2 usage for glucose synthesis?
• Name a structure found on stems which allow gas exchange.
• From which substance is oxygen produced during photosynthesis?
• In what main part of a plant does most photosynthesis take place?
• How many molecules of CO2 are needed to make one glucose molecule?
• What are the overall products of the light-dependent reactions?
• What is the fate of the carbon in the carbon dioxide used in the dark stage of photosynthesis?
• What is meant by the term photosynthesis?
• The oxygen produced in photosynthesis originates from which molecule?
• During the Calvin cycle, which step involves the reduction of 3-phosphoglycerate to glyceraldehyde-3-phosphate?
• What happens when stomata are opened during photosynthesis?
• Which gas produced in photosynthesis is released by leaves and used by other organisms?
• In C4 photosynthesis, CO2 is fixed in mesophyll cells by which enzyme and transported to bundle-sheath cells?
• Why are aquatic plants such as Elodea suitable for investigating photosynthesis?
• Where do the light-dependent reactions occur in the chloroplast?
• Which organelle is the site of photosynthesis?
• Which enzyme fixes CO2 in C3 photosynthesis in the mesophyll cells?
• Where does the Calvin cycle take place within the chloroplast?
• What is a possible product formed from carbon dioxide during photosynthesis?
• Which observation indicates photosynthesis is occurring in aquatic plants?
• What are the main reactants and products of the Calvin cycle?
• Which gas is essential for photosynthesis?
• Why must the first stage occur before the second stage in photosynthesis?
• Describe cyclic photophosphorylation and when it occurs.
• What is the net chemical equation for photosynthesis using common shorthand?
• Name two environmental factors on which the rate of photosynthesis depends.
• Which statement describes the fate of the oxygen produced during photosynthesis?
• Identify the two photosystems and their primary pigments.
• What term describes the nutrition of plants?
• Which statement best describes a potential benefit of having more than one chlorophyll pigment?
• Why is a suitable temperature necessary for the dark stage of photosynthesis?
• How is the proton gradient across the thylakoid membrane established for ATP synthesis?
• Why is the dark stage given the alternative name of the light-independent stage?
• True or False: Photosynthesis occurs in both prokaryotic and eukaryotic organisms.
• The Calvin cycle takes place in which part of the chloroplast?
• Which molecule donates electrons and protons to CO2 during the dark stage?
• Which is a fate of the oxygen produced during photosynthesis?
• What is the net product of the Calvin cycle after fixing three CO2 molecules?
• Why is temperature important for photosynthesis, and what happens at high temperature?
• In the Calvin cycle, what is the purpose of RuBP regeneration?
• What is the source of the oxygen released during photosynthesis?
• What occurs when stomata close during photosynthesis?
• Which gas is produced as a byproduct of photosynthesis?
• What is the main source of carbon dioxide used by plants in the dark stage of photosynthesis?
• Name the group of biological catalysts which control photosynthesis.
• Which are the three main phases of the Calvin cycle?
• To what group of biomolecules do the main products of the dark stage belong?
• In the second stage compounds of the general formula Cx(H2O)y are formed. What name is given to this group of compounds?
• Which pigments contribute to photosynthesis and why is pigment diversity important?
• The energy for photosynthesis is captured from which source?
• What supplies energy to the dark stage of photosynthesis?
• Which leaf layer contains more organelles for photosynthesis?
• Through which tiny openings in the leaf does gas exchange primarily occur?
• Carbon dioxide is released from plants via which two processes?
• Which factors can limit the rate of photosynthesis and how is the limiting factor determined?
• Two products of the light stage vital for the dark stage are NADPH and ATP. Which are they?
• Which equation correctly represents photosynthesis?
• What is the main purpose of the dark stage?
• What do the letters ATP stand for?
• In which stage does ATP form?
• Where is NADPH formed during the light-dependent reactions?
• Which gas is fixed into organic molecules during photosynthesis?
• In which stage of photosynthesis does carbon dioxide provide carbon for carbohydrate formation?
• Photosynthesis occurs in which types of organisms?
• The cells in the palisade layer of a leaf contain many organelles that carry out photosynthesis. Suggest why the cells here contain more of these organelles than the cells in the mesophyll.
• What is photophosphorylation and how many ATP are produced per NADPH in non-cyclic flow?
• In photosynthesis, what is the role of NADP-?
• What is the energy cost to fix one CO2 into a sugar precursor in the Calvin cycle?
• Light energy is converted into what form during photosynthesis?
• Which pigment primarily absorbs light for photosynthesis?
• What does ADP stand for?
• What is the chemical formula for glucose?
• Which colour of light is not absorbed by plants?
• How does water availability affect photosynthesis in leaves?
• Describe non-cyclic electron flow and its outputs.
• Which pigment class helps protect photosystems by dissipating excess light energy as heat?
• What does the Hill reaction demonstrate about photosynthesis?
• Which statement best describes why light-dependent reactions are essential for photosynthesis?
• Which molecule produced in the light-dependent stage carries reducing power to the dark reactions?
• What is the stoichiometry of ATP and NADPH required per CO2 fixed in the Calvin cycle?
• What can cause a decrease in chlorophyll content and how does this affect photosynthesis?
• Which molecule leaves the Calvin cycle to be used in biosynthesis for the plant?
• Where is NADPH formed in the light-dependent reactions?
• In a leaf, where would you expect to find the greatest concentration of chlorophyll?
• Which set of products results from the photolysis of water during photosynthesis?
• Which energy carriers are produced by the light-dependent reactions and supplied to the Calvin cycle?
• Where are chloroplasts predominantly located in the leaf to maximize photosynthesis?
• What is the role of PEP carboxylase in C4 photosynthesis?
• What is the role of water in photosynthesis according to the material?
• Which provides the energy carrier for the dark stage to proceed?
• Name a gas essential for the dark stage of photosynthesis.
• Which stage of photosynthesis captures light energy to synthesize ATP and NADPH?
• Which leaf tissue is known for having many chloroplasts to maximize light capture?
• What is RuBP and what is its role in photosynthesis?
• What is the role of ATP synthase in chloroplasts?
• Why is RuBisCO considered inefficient, and how do plants mitigate this?
• Which two pathways are cited as plants’ strategies to mitigate RuBisCO inefficiency?
• What is a key difference between the light-dependent and light-independent reactions of photosynthesis?
• Which component of the chloroplast is most directly involved in carbon fixation?
• Explain the role of carotenoids in photosynthesis beyond light absorption.
• What is the role of NADP in photosynthesis?
• In a controlled experiment with an aquatic plant, how could you determine the rate of photosynthesis?
• What does NAD stand for?
• Which cell organelle is primarily involved in photosynthesis?
• What is the relationship between the rate of photosynthesis and either the light intensity or the carbon dioxide concentration?
• Which gas is released as a byproduct of photosynthesis?
• Which statement describes a process that releases carbon dioxide into the air?
• To boost photosynthesis in a greenhouse, which change would be effective?
• Which pigment-containing organelle captures light energy for photosynthesis?
• Which stage uses light energy to synthesize ATP and NADPH?
• In a leaf, the region containing the most chlorophyll is the?
• In the Calvin cycle, which molecule is regenerated to allow continued CO2 fixation?
• How many CO2 molecules are required to synthesize one molecule of glucose in photosynthesis?
• During the reduction phase of the Calvin cycle, which statement correctly describes the fate of 3-PGA?
• Where does the Calvin cycle take place in chloroplasts?
• During oxygenic photosynthesis, which molecule is released as a byproduct?
• What gas is released during photosynthesis?
• What is the role of ATP in photosynthesis?
• What is the role of ferredoxin in photosynthesis?
• How does chlorophyll function in light absorption and energy transfer?
• In which cell organelle is chlorophyll found?
• Which gas from the air do plants primarily use for photosynthesis?
• Which statement is true about the overall outcome of photosynthesis?
• Is energy released or absorbed during photosynthesis?
• Where does carbon dioxide enter the leaf?
• How many NADPH and ATP are required to fix three CO2 in the Calvin cycle?
• If CO2 concentration increases in C3 plants at moderate temperatures, what is the typical effect on photosynthesis?
• Where does the electron released from splitting water go?
• Which of the following is the product formed from carbon dioxide during the dark stage of photosynthesis?
• Which plant type is particularly efficient in hot and dry conditions due to CO2 concentration mechanisms?
• Which of the following would most effectively increase the rate of photosynthesis in a greenhouse?
• During photosynthesis light energy is converted into which form of energy?
• How do leaves adapt to high light intensity to prevent photodamage?
• Which statement best describes the energy change in photosynthesis?
• Name the cell structures, present in large numbers in the upper part of the leaf that are needed for photosynthesis.