Name the following:

1. The kind of microscope that consists of a single biconvex lens.
2. The kind of mirror used for throwing light on the object in Hooke's microscope.

Name the following:

1. Any two one-celled organisms.
2. The longest cells in animals.
3. Amoeboid cells in humans.
4. Shape of white blood cells.

A large surface area/volume ratio of the cells ensure a greater diffusion of certain substances into the cell. Name such substances.

Name the part of cell in which

1. many chemical reactions occur with the help of enzymes.
2. a network of chromatin fibres occurs.
3. cellulose forms the main component.