Biology, Week: 2
Topic: Structure of Plant and Animal Cell
The cell is composed of protoplasm which can be divided into two main parts namely;
- The cytoplasm
- The nucleus
Each cell is bounded by a thin membrane. The cytoplasms are fluid materials that consist of cytoplasmic organelles such as Lysosome, golgi bodies, endoplasmic reticulum, and mitochondria, etc.
The nucleus is bounded by a nuclear membrane and it consists of chromosomes and nucleolus.
The animal cell in addition has centrosome. It also has starch granules, cellulose cell wall and some plastid e.g. chloroplast. The table below shows some cell organelles and functions.
|
Cell Organelles |
Functions |
|
Nucleus |
It controls all life activities of the cell. |
|
Chromosome |
It controls the DNA which stores genetic traits. |
|
Mitochondria |
It is described as the power house of the cell. |
|
Vacuole |
It contains cells sap which act as an osmoregulation by helping to remove excess water in cells. |
|
Nucleolus |
It produces the ribosome for protein synthesis. |
|
Endoplasmic reticulum |
It aids the transport of materials within the cytoplasm. |
|
Golgi bodies |
It functions in synthesis, packaging and distribution of materials. |
|
Chloroplasts |
They contain chloroplast which aids photosynthesis in green plants. |
|
Lysosomes |
They are sites for respiratory enzymes. |
|
Ribosomes |
They are responsible for protein synthesis. |
|
Cell wall |
It provides protection, shape and mechanical support for the cell. |
|
Centrioles |
They are important in cell division. They may also serve as basal body from which flagella or cilia arise. |
|
Starch granules |
They store starch for cell. |
Similarities between Plant and Animal Cell
Both plant and animal cells have in common the following organelles;
- Nucleus
- Mitochondria
- Cytoplasm
- Ribosome
- Cell membrane
- Lysosome
- Chromosome
- Endoplasmic reticulum
- Golgi bodies
- Nucleolus
The Difference between Plant Cell and Animal Cell
|
Plant Cell |
Animal Cell |
|
Plant cell has chloroplast |
Animal cell has no chloroplast |
|
It is usually rectangular and definite in shape |
Animal cell is usually spherical |
|
It has rigid cell wall |
It has no cell wall |
|
It has no flexible cell membrane |
It has flexible cell membrane |
|
It has a large vacuole |
It has a small vacuole |
