Posted by Structures of Plant and Animal Cells and Functions of Their Components
Structure of the cell: The structure of plant cell and animal cell can fully be understood through the use of microscope. The cell is composed of protoplasm which can be divided into two main parts: the cytoplasm and nucleus. Each cell (plant or animal) is bounded by a thin membrane. The cytoplasm is a fluid material that consists of cytoplasmic organelles such as lysosome, golgi bodies, endoplasmic reticulum, mitochondria, vacuoles etc. The nucleus is bounded by a nuclear membrane and it consists of chromosomes (chromatin granules) and nucleolus.
The animal cell in addition has centrosomes. The plant cells in addition also has starch granules, cellulose cell wall and some plastids, e.g. chloroplasts. The structure and functions of the components of the cells of organelles are outlined in the below.
| Cell components
or Organelles |
Description of Structure | Functions of cell components |
| i) Nucleus | The nucleus has aspherical body which
is covered by a double membrane which contains hereditary materials. chromosome and genes often centrally located in the cell, embedded in cytoplasm. |
(i) It controls all life activities of the cell.
(ii) It stores hereditary information as it contains DNA inside chromosomes which take part in cell division.
|
| (ii) Chromosome | These are located in the nucleus and
contain deoxyribonucleic acid or DNA |
It contains the DNA which stores genetic
traits |
| (iii) Mitochondria | These are oval or rod-shaped. They are
bounded by a double membrane. The inner membrane is folded and the interior is filled with matrix. The matrix contains ribosomes. |
It is described as the power-house of the
cell. They are sites of respiration or where energy is released from simple sugar. |
| (iv) Vacuole | It occupies a large central portion of plant
cell. It is lined with a membrane and filled will cell sap. The cell sap acts as a “store house” for many substances. |
It contains cells sap which act as an
Osmo-regulator by helping to remove excess water in cells.
|
| (iv) Nucleolus | They are dense structures within the
nucleus. |
They produce the ribosome for protein
synthesis. |
| (vi) Endoplasmic | They are membrane-like structures that
reticulum form channels within the cytoplasm |
Aid the transport of materials
within the cytoplasm. |
| (vii) Golgi bodies | These are series of disc-shaped sacs. | They function in synthesis, packaging
and distribution of materials. |
| (vii) Chloroplasts | These are large green organelles in plant
cells. They contain chlorophyll. |
They contain chlorophyll which aid
photosynthesis in green plants |
| (ix) Lysosomes | These are thin-wall bodies and they
contain enzymes |
They are sites for respiratory enzymes. |
| (x) Ribosomes | These are small round bodies attached to
endoplasmic reticulum. |
They are responsible for protein
synthesis. |
| (xi) Cell wall | It is a tough, fairly rigid structure that
is freely permeable in plant cells. |
(i) It provides protection, shape and
mechanical support for the cell. (ii) It also allows free passage of nutrients in and out of the cell. |
| (xii) Cell membrane | This is a flexible membrane made up
of mainly proteins and lipids. It is selectively permeable. |
(i) It plays a great role in selective
absorption of materials. (ii) It also protects the cell. |
| (xiii) Centrioles | These are two small granules near
nucleus of animal cells from which flagella or cilia arise. |
They are important in cell division.
They may also serve as basal body |
| (xiv) Starch granules | These are oval or round structures
mostly found in plant cells. |
They store starch for the cell. |