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Free International Baccalaureate Diploma Programme Exam Style Questions
Refine your grasp of International Baccalaureate Biology with our specially curated IB exam questions. These questions cover a range of topics, aiding in your preparation and understanding of essential Biology concepts required for the IBDP curriculum and exams.
Question 1
A student draws an E.coli bacterium to scale using a magnification of $\times$ 500. What is the actual size of the bacterium given that the student's drawing has a diameter of 0.9 mm?
[ 1 ]
A.
18 µm
B.
0.18 mm
C.
1.8 µm
D.
0.018 mm
Rationale
actual size = image size $\div$ magnification
actual size = 0.9 mm $\div$ 500 = 0.0018 mm = 1.8 µm
Question 2
The salt concentration inside an animal cell is 2 %. The cell is placed in a medium with a salt concentration of 7%. What will happen to the cell in these new conditions?
[ 1 ]
A.
The cell will gain salt from the medium.
B.
The cell will lose salt to the medium.
C.
The cell will shrink from loss of water.
D.
The cell will remain unchanged.
Rationale
Osmosis is the movement of water molecules across a semi-permeable membrane from a region of high water potential (low solute concentration) to a region of low water potential (high solute concentration).
Thus water molecules will move from the cell (region of higher water potential) to the medium (region of lower water potential).
Question 3
What is the difference between facilitated diffusion and simple diffusion?
[ 1 ]
A.
Facilitated diffusion is an active process whereas simple diffusion is passive.
B.
Facilitated diffusion requires channel proteins whereas simple diffusion does not.
C.
Net movement of particles is against a concentration in facilitated diffusion.
D.
Net movement of particles is against a concentration in simple diffusion.
Question 4
The percentage of uracil in the RNA of an organism is approximately 30 %. What is the percentage of cytosine?
[ 1 ]
A.
60 %
B.
30 %
C.
15 %
D.
20 %
Rationale
If uracil bases make up 30% of all base pairs in DNA, the amount of the corresponding base adenine would also be 30%. The remaining 40% of bases are composed of cytosine and guanine in equal amounts since they are complementary. Thus the percentage of cytosine/guanine is 20%.
Question 5
What is light energy used for in photolysis during photsynthesis?
[ 1 ]
A.
For the formation of oxygen and hydrogen
B.
For the formation of carbon dioxide
C.
For the formation of ATP and glucose
D.
For the formation of oxygen
Rationale
Photolysis uses light energy to split water molecules into oxygen, hydrogen/protons and electrons.
2H2O → O2 + 4 H+ + 4 e-
Question 6
Which structures are represented by labels I and II in the following image?
| I | II | |
|---|---|---|
| A. | chromosome | spindle fibre |
| B. | chromatid | centriole |
| C. | centromere | spindle fibre |
| D. | chromosome | centriole |
[ 1 ]
[2022. Mitosis. [image] Available at: <https://pixabay.com/> [Accessed 2 August 2022].]
A.
A
B.
B
C.
C
D.
D
Question 7
The diagram below shows the action spectrum of a green plant. What conclusion can be drawn from it?
[ 1 ]
[© Abaccus Ltd 2022]
A.
Yellow light promotes photosynthesis.
B.
Every colour of the spectrum contributes equally to photosynthesis.
C.
Light of wavelength 550 nm is the most effective at promoting photosynthesis.
D.
Light of wavelength 550 nm is not effective at promoting to photosynthesis.
Question 8
What can this molecule be hydrolysed into?
[ 1 ]
[© Abaccus Ltd 2022]
A.
Monosaccharides
B.
Amino acids
C.
Fatty acids
D.
Nucleotides
Rationale
Proteins contain nitrogen and sulfur. Carbohydrates and lipids do not.
The subunits of proteins are amino acids.
Question NaN
A student draws an E.coli bacterium to scale using a magnification of $\times$ 500. What is the actual size of the bacterium given that the student's drawing has a diameter of 0.9 mm?
[ 1 ]
A.
18 µm
B.
0.18 mm
C.
1.8 µm
D.
0.018 mm
Rationale
actual size = image size $\div$ magnification
actual size = 0.9 mm $\div$ 500 = 0.0018 mm = 1.8 µm
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