Question 2
Which statement about cardiac muscle fibres is correct?
The right answer is the one marked above.
They bear intercalated discs. Those are the junctions between cardiac muscle cells, and they let the signal cross from one cell to the next.
This is question 1(vi) of the chapter exercise. Cardiac fibres are striated, uninucleate and branched — the branching is what makes the heart contract as one unit.