Questions

The endomembrane system is composed of the different membranes that are suspended in the cytoplasm within a eukaryotic cell. These membranes divide the cell into functional and structural compartments or organelles. In eukaryotes, the organelles of the endomembrane system include the nuclear membrane, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vesicles, endosomes and the cell membrane, among others.

In music, a fugue is a contrapuntal compositional technique in two or more voices, built on a subject that is introduced at the beginning in imitation and which recurs frequently in the course of the composition. 

Hence, the main theme of a fugue is called the subject.

Nucleus serves as the control center for cell metabolism and reproduction.

In dealing with a coil spring the spring constant will depend on the stiffness of the spring material, the thicknessof the wire from which the spring is wound and, diameterof the turns of the coil, the number of turns per unit length and the overall length of the spring.

Astigmatism is a common vision condition that causes blurred vision. It occurs when the cornea is irregularly shaped or sometimes because of the curvature of the lens inside the eye.