The picture shows a group of muscle cells in the heart. all of these muscle cells beat in unison to push blood in timing with the rhythm of the heart, at the direction of nearby nerve cells.

these muscle cells could best be called a
a) organ.
b) tissue.
c) macromolecule.
d) organ system.

How many variables are altered in a good experiment? a.1 b.0 c.2 d.3

Name the organs of humanelemintary canal.

45 points how are people today being protected from tsunamis? earthquake data is analyzed to detemrine if a tsunami is likely, and if so, warnings are sent out. areas in tsunami risk zones are no longer heavily populated. radar is used to measure wave heights regularly. meteorologists study the winds to determine if wave heights will be large.