Eukaryotic Cell: Definition, Features, Structure, Examples

The Eukaryotic cell is the most advanced type of cell which is present in both animals and plants. Dougherty (1957) has divided cells into two types (based on the organization in the nucleus of the cell) – The Prokaryotic cell and the Eukaryotic cell. Eukaryotic cells having a well-organized nucleus (nuclear membrane, nucleolus, and nuclear reticulum are present within the nucleus).

The name Eukaryotic is derived from the Greek words Eu and Karyon.
Eu = Typical and Karyon = nucleus

Eukaryotic cells are relatively large in size (0.5-12 μm) and containing membrane-bound cell organelles such as mitochondria, plastids, Golgi bodies, etc. The organisms having Eukaryotic cells are called Eukaryotes.

Definition:

The cells having a well-organized nucleus, containing membrane-bound cell organelles (mitochondria, plastids, Golgi bodies, etc) and chromosomes with basic proteins, are called Eukaryotic cells.

Features of Eukaryotic cell:

1. Eukaryotic cells are relatively large in size (0.5-12 μm).
2. The cell wall of plant cells is made of cellulose and pectin. However, animal cells do not have a cell wall, but in many cases contain glycocalyx
3. Present membrane-bound cell organelles. Like – Mitochondria, Golgi bodies, endoplasmic reticulum, plastids, lysosome, etc.
4. The ribosomes present freely in the cytoplasm or attached to the surface of the endoplasmic reticulum of the cells. Ribosomes are of 80s type.
5. The well-organized nucleus is present. The nucleus consists of the nuclear membrane, nucleolus, nuclear reticulum, and nucleoplasm.
6. Histone proteins are present in the cells. DNA forms chromosomes mainly with the help of histone proteins and some non-histone proteins.

Fig: Labelled diagram of Eukaryotic cell showing well-formed nucleus

7. In some plants (like – Dictyota, Fucus, Yeast) and animals cell, the centrosome is present. Centrosomes formed mitotic apparatus in the animal cells.
8. Mitotic apparatus is formed during cell division.
9. Cell division is accomplished by the method of amitosis, mitosis, and meiosis.
10. Respiratory pigments are present in the cytoplasm and within mitochondria.
11. Flagella are composed of microtubules if present.
12. Vacuoles are present in the cytoplasm of the plant cells. Animal cells usually do not have vacuoles.

Examples:

Plant cells and animal cells are examples of Eukaryotic cells.

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