The nuclear structure of plant and animal cells is same but the nucleus of bacterial cell is different. It is not well organised. It and does not have nuclear membrane and nucleolus. The genetic material is present in special region. Therefore, bacteria is called prokaryotes while plants and animals are eukaryotes.

Given figure in question, represents a plant cell. The various parts of plant cells are labelled as follows:

Cells were discovered by Robert Hooke in 1665. He observed a thin slice of cork (part of bark of a tree) under a simple microscope and saw that it was made up of small box-like structures. These boxes appeared like a honeycomb, with one box separated from other by a partition. Hooke coined the term 'cell' for each box

Difference between plasma membrane and cell wall are:

(a) Cytoplasm It is a jelly-like substance, present between the cell membrane and the nucleus. It encloses tiny structures called cell organelles that perform different functions. It also contains water, sugar, proteins, minerals, etc.
(b) Nucleus of a cell It is a spherical component of cell commonly located in the centre of cell. It is covered by porous nuclear membrane and contains genetic material like RNA and DNA. It also contains thread-like structures called chromosomes which carry genes. Nucleus controls various activities of the cell and play role in inheritance.

Mitochondria are called the 'powerhouse' of the cell because they provide energy for all the activities of the cell by oxidising food.

Amoeba and Paramecium are unicellular prokaryotic organisms.

Man and dog are multicellular organisms.

Nails and hair are made up of dead cells. They do not have protoplasm and nerve cells, hence one does not feel pain, when they are clipped or cut.

The cell organelle is chloroplast and chlorophyllis the pigment responsible for green colourof leaves

(a) Chromoplasts are the coloured plastids (except green) that give fruit and flower their colour.
(b) Chloroplasts are known as 'kitchen of the cell
(c) No, all plastids are not coloured. Leucoplasts are the colourless plastids.
(d) No, we will not see plastids in an animal cell as it is devoid of plastids.
(e) Rohit is inquisitive, attentive and has love and care towards nature

Organelles are distinct, highly organised structures that perform specialised functions within the cell.
The organelles that are found in most cells are mitochondria, ribosomes and vacuole.
Functions of nucleus
(i) It is concerned with the transmission of hereditary traits from the parent to offspring (i.e.inheritance).
(ii) It controls all the metabolic activities of the cell (i.e. control centre of cell activities).