IB myp 4-5 Biology – Practice Questions- All Topics
Topic :Process-Photosynthesis
Topic :Process– Weightage : 21 %
All Questions for Topic : Photosynthesis; transport in plants; xylem; phloem; transpiration and translocation; roots; tropisms; monocots and dicots; structure of leaf and stem; rate of transpiration and factors affecting it
Question
Question (8 marks)
Investigating how changing light levels affect photosynthesis.
4a.Select the correct location for each word to show the equation for photosynthesis. (1 mark)
▶️Answer/Explanation
Ans: Carbon dioxide + Water + Sunlight → Glucose + Oxygen
Question
b. Cabomba is an aquatic plant that is often used for photosynthesis experiments. Cabomba releases gas bubbles so is useful for this type of experiment. The image below shows a typical set-up for plant photosynthesis experiments.(4 marks)
Identify the variables in this investigation.
Independent variable
Dependent variable
Control variable 1
Control variable 2
▶️Answer/Explanation
Ans: In this investigation, the independent variable would be the type or presence of the Cabomba plant. The dependent variable would be the number or rate of gas bubbles released. The control variable 1 could include factors like the amount of light, temperature and control variable 2 could be water conditions that are kept constant throughout the experiment
Question
c.Formulate a hypothesis for this investigation.
If the distance between the plant and the light source increases then(3 marks)
▶️Answer/Explanation
because
Ans: If the distance between the plant and the light source increases, then the plant’s photosynthesis rate may decrease because the intensity of light reaching the plant decreases with distance.