The figure below shows an electron micrograph of a portion of one insect flight muscle cell.Identify the structures labeled A and B.
A) A = actin and myosin filaments;B = gap junctions
B) A = T tubules;B = sarcoplasm
C) A = actin and myosin filaments;B = mitochondria
D) A = T tubules;B = mitochondria
E) A = sarcoplasm;B = gap junctions

Question

The figure below shows an electron micrograph of a portion of one insect flight muscle cell.Identify the structures labeled A and B. 
A) A = actin and myosin filaments;B = gap junctions 
B) A = T tubules;B = sarcoplasm 
C) A = actin and myosin filaments;B = mitochondria 
D) A = T tubules;B = mitochondria 
E) A = sarcoplasm;B = gap junctions

Quizplus · Accepted Answer

The structures labeled A are actin and myosin filaments, which are the contractile elements of muscle cells. The structures labeled B are mitochondria, which are responsible for producing ATP, the energy source for muscle contraction. The image does not show any gap junctions, which are structures that allow for communication between cells. The T tubules, which are extensions of the cell membrane that help propagate electrical signals throughout the cell, are not clearly visible in the image.

The Figure Below Shows an Electron Micrograph of a Portion