Explain Characteristics and Type of Cells.

Question:

Explain Characteristics and Type of Cells.

Answer:

Characteristics of Cells:

Following are the various essential characteristics of cells:

• Cells provide structure and support to the body of an organism.
• The cell interior is organized into different individual organelles surrounded by a separate membrane.
• The nucleus (major organelle) holds genetic information necessary for reproduction and cell growth.
• Every cell has one nucleus and membrane-bound organelles in the cytoplasm.
• Mitochondria, a double membrane-bound organelle is mainly responsible for the energy transactions vital for the survival of the cell.
• Lysosomes digest unwanted materials in the cell.
• Endoplasmic reticulum plays a significant role in the internal organization of the cell by synthesizing selective molecules and processing, directing and sorting them to their appropriate locations.

Types of Cells:

Cells are similar to factories with different labourers and departments that work towards a common objective. Various types of cells perform different functions. Based on cellular structure, there are two types of cells:

• Prokaryotes
• Eukaryotes

Prokaryotic Cells

1. Prokaryotic cells have no nucleus. Instead, some prokaryotes such as bacteria have a region within the cell where the genetic material is freely suspended. This region is called the nucleoid.
2. They all are single-celled microorganisms. Examples include archaea, bacteria, and cyanobacteria.
3. The cell size ranges from 0.1 to 0.5 µm in diameter.
4. The hereditary material can either be DNA or RNA.
5. Prokaryotes generally reproduce by binary fission, a form of asexual reproduction. They are also known to use conjugation – which is often seen as the prokaryotic equivalent to sexual reproduction (however, it is NOT sexual reproduction).

Eukaryotic Cells

1. Eukaryotic cells are characterized by a true nucleus.
2. The size of the cells ranges between 10–100 µm in diameter.
3. This broad category involves plants, fungi, protozoans, and animals.
4. The plasma membrane is responsible for monitoring the transport of nutrients and electrolytes in and out of the cells. It is also responsible for cell to cell communication.
5. They reproduce sexually as well as asexually.
6. There are some contrasting features between plant and animal cells. For eg., the plant cell contains chloroplast, central vacuoles, and other plastids, whereas the animal cells do not.