IB MYP Integrated Sciences e-Assessment : Photosynthesis Exam Style Practice Questions - New Syllabus
Question (10 marks)
Topic: Systems (Photosynthesis)
To colonize Mars, we need to find a way to grow food. Soil is heavy and takes up too much space on a rocket, so scientists have been experimenting with growing plants in space using as little soil as possible. Using methods like hydroponics, plants can be grown using a nutrient-rich solution rather than soil.
Question a (2 marks)
Topic: Photosynthesis
State the products of photosynthesis by completing the word equation below.
▶️Answer/Explanation
Answer:
carbon dioxide + water → Glucose + Oxygen
Explanation:
Photosynthesis is the process by which plants convert carbon dioxide and water into glucose and oxygen using sunlight. The glucose is used as an energy source for the plant, while oxygen is released as a byproduct.
Question b (1 mark)
Topic: Elements
Plants need nutrients such as phosphorus, magnesium, and nitrogen to be able to grow.
Classify the nutrients shown as compounds, elements, or mixtures.
✔ Select
- Compounds
- Elements
- Mixtures
▶️Answer/Explanation
Answer:
Elements
Explanation:
Phosphorus (P), magnesium (Mg), and nitrogen (N) are all elements. They are pure substances that cannot be broken down into simpler substances by chemical means.
Question c (2 marks)
Topic: States and Properties of Matter
Suggest why plants do not need soil to grow.
▶️Answer/Explanation
Answer:
Plants do not need soil to grow because they can obtain all the necessary nutrients from a nutrient-rich solution in hydroponics.
Explanation:
Soil is primarily used to provide plants with nutrients and support. In hydroponics, plants are grown in a nutrient-rich water solution, which supplies all the essential nutrients directly to the roots, eliminating the need for soil.
Question d (2 marks)
Topic: Photosynthesis
Plants need to absorb light for growth. The color of light absorbed by plants depends on the pigments they contain. The graph below shows the colors of light which are absorbed by a plant containing the pigment chlorophyll.
Using the graph, explain why different colors of light affect plant growth.
▶️Answer/Explanation
Answer:
Plants containing chlorophyll absorb a high percentage of blue or red light, while the absorbance of green light is low. This is because chlorophyll reflects green light, which is why plants appear green.
Explanation:
Chlorophyll, the primary pigment in plants, absorbs light most efficiently in the blue and red regions of the spectrum. Green light is not absorbed as effectively, which is why plants appear green. The absorption of blue and red light is crucial for driving the photosynthetic process, which in turn affects plant growth.
Question e (3 marks)
Topic: Digestion
One of the first plants to be grown in space was the pea plant. Peas are a good source of protein.
Explain how the protein in the peas would be digested in the astronaut’s stomach.
▶️Answer/Explanation
Answer:
HCl (hydrochloric acid) in the stomach activates enzymes like pepsin, which break down proteins into amino acids.
Explanation:
In the stomach, hydrochloric acid creates an acidic environment that activates the enzyme pepsin. Pepsin then breaks down the protein molecules from the peas into smaller peptides and amino acids, which can be absorbed by the body.