Which option correctly identifies the parts labeled $a$ and $b$ in the given figure?

$A$ student wants to study cell structure using a light microscope with a $10X$ eyepiece and a $45X$ objective lens. To obtain the best resolution,which color of light should be used to illuminate the specimen?

Subcellular components can be separated by the help of . . . . . . .

Which of the following statements is/are correct?
$(i)$ The endomembrane system includes plasma membrane,$ER$,Golgi complex,lysosomes and vacuoles.
$(ii)$ $ER$ helps in the transport of substances,synthesis of proteins,lipoproteins and glycogen.
$(iii)$ Ribosomes are involved in protein synthesis.
$(iv)$ Mitochondria help in oxidative phosphorylation and generation of $ATP$.

Both plants and animals are provided with

Cytoplasmic streaming movement is the characteristic of