Cells and Organisms
Structure of plant cell
Structure of animal cell
In cell biology, an organelle is one of several structures with specified functions, suspending in the cytoplasm of a eukaryotic cell, or prokaryotic cell.
Examples of which include:
- Endoplasmic Reticulum
- Golgi Complex
- Chloroplast (plant cells)
- … and more
Unlike in eukaryotic cells, prokaryotic cells do not contain membrane-bound organelles. However, they do contain some non-membranous organelles such as ribosomes flagella, and plasmids (circular DNA structures that are not involved in reproduction).
Eukaryotic cells have a true nucleus.
- The nucleus houses DNA
Prokaryotic cells do *not* have a true nucleus
- Their DNA is not separated from the rest of the cell, but is coiled up in whats called a nucleoid.
Differences Between Plan and Animal Cells
|1||Usually larger in size||Comparatively smaller|
|2||Enclosed by rigid cellulose cell wall in addition to plasma membrane||Only enclosed by a thin flexible plasma membrane|
|3||It cannot change it’s shape||Can often change it’s shape|
|4||Plastids are present. Plants exposed to sunlight contain chloroplast||Plastids are usually absent|
|5||A mature plant contains a large central vacuole||Often possesses many small vacuole|
|6||Nucleus resides on the same side of the peripheral cytoplasm||Nucleus usually lies in the centre|
|7||Centrioles are usually absent||Centrioles are practically present|
|8||Lysosomes are rare||Lysosomes are always present|
|9||Glyoxysomes may be present||Glyoxysomes are absent|
|10||Tight junctions and desmosomes are lacking. Plasmodesmata is present||Tight junctions and desmosomes are present between cells. Plasmodesmata is absent|
|11||Reserve food is generally stored starch||Reserve food is usually glycogen|
|12||Plant cells synthesize all amino acids, enzymes, and vitamins required||Animal cells cannot synthesize all required amino acids, enzymes, and vitamins required|
|13||Spindles formed during cell division in anastral – without esters at opposite polls||Spindle formed during cell division is amphiastral. Has an ester at each poll|
|14||Cytokinesis occurs by cell plate method||Cytokinesis occurs by construction or furrowing|
|15||Plant cells do not burst if placed in hypotonic solution due to the cell wall||Animal cells lacking contractile vacuoles usually burst if placed in hypotonic solution|