The invention of the microscope was a great boon for people to study smaller objects or micro-organisms. Scientists made different microscopes by using different types of lenses for magnification.
Gaurav made a table of two scientists and the kind of microscope they invented.

Identify P and Q

1. P — Simple microscope, Q — Compound microscope.
2. P — Electron microscope, Q — Simple microscope.
3. P — Compound microscope, Q — Electron microscope.
4. P — Compound microscope, Q — Simple microscope.

Given below is the structure of nucleus of a cell. Read the information below the diagram and fill in the blanks:

Nucleus is the most important part of the cell. It is located in the central area in animal cells but pushed towards the periphery in plant cells due to the presence of a large vacuole in the centre. It regulates and coordinates various life processes of the cell and also plays an important role in cell division.

Nucleus has a delicate, protective surrounding layer (a) …………… which is filled with a relatively dense fluid (b) …………… . There are certain thread-like structures suspended in the fluid called (c) …………… . These thin thread-like fine structures become thick and ribbon-like during the time of cell division. These prominent ribbon-like structures are called (d) …………… .Nucleus contains a spherical, dense body inside it, called as (e) …………… which participates in protein synthesis.

State whether the following statements are true (T) or false (F):

(a) All animal cells contain a cell wall.

(b) The cell wall is made of protein.

(c) Centrosome occurs in animal cells.

(d) Plant cells contain large vacuoles.

(e) Protoplasm is the part of the cell which surrounds the nucleus.

(f) Genes are located in chromosomes.

(g) Anthocyanin are the pigments of flowers, which are dissolved in cell-sap.

How many chromosome pairs are found in human cells?