Plasmodesmata are found between A. Sieve tube cells. B. Companion cells. C. Vess
ID: 82527 • Letter: P
Question
Plasmodesmata are found between A. Sieve tube cells. B. Companion cells. C. Vessel elements. D. Tracheid E. Meristematic cells. What keeps the ventricles from contracting at the same time as the atria? A. Nerves from the brain conduct separate signals to the atria and ventricles. B. The atria and ventricular pacemakers touch off contractions at different times. c. The sinoatrial node sends separate signals to the atria and ventricles. D. The atrioventricular node delays the signal from the sinostrial node. E. A and B only.Explanation / Answer
Answer 18: A (As explained below)
Plasmodesmata are part of the symplastic pathway and are seen connecting two neighboring sieve tube cells.
Answer 19: D (As explained below)
When the sinoatrial node fires, the impulse travels to the atrioventricular node but gets held up before continuing further. hence Option d is the correct answer.