Practise IB Biology HL B2.3 with evidence-led questions on stem-cell potency, differentiation, exchange surfaces and the structure–function adaptations of specialized cells.
A liver cell and a neuron developed from the same zygote both retain genes L and N. RNA from L is abundant in the liver cell but scarce in the neuron; RNA from N shows the opposite pattern.
Which interpretation best explains how these cells can become specialized?
The two cells must use different genetic codes to translate the same genes.
Each cell must delete every gene that it does not currently express.
Different expression of shared genes can produce different sets of proteins.
Retaining the same genes requires the two cells to have identical protein production.
Outline reasons for the therapeutic use of stem cells.
State what change there has been in the cell surface area to volume ratio in red blood cell 1.
The micrograph shows part of a cell.
Which principal function is this cell likely to have, as judged by its cell structure and organelles?
High rate of protein processing
High rate of absorption
High rate of photosynthesis
High rate of movement
Measurements of the lung capacity of a student were recorded using a spirometer and displayed with a data logger. Initially the student was at rest, then changed to carrying out strenuous exercise. The results are displayed in the graph.
Outline the function of pneumocytes in the lungs.
Which features are found in both cardiac and striated muscle?
Nuclei and branched myofibrils
Sarcomeres and unbranched myofibrils
Mitochondria and branched myofibrils
Sarcomeres and mitochondria
Draw a labelled diagram of a mature human egg.