Recognise the various stages of cell cycle.
⭕️ Cell Cycle
👆🏻This photo showing all the stages in cell cycle.
In HKDSE Biology examination, remember what is happening in each of the three main stages (interphase, mitosis/meiosis, cytokinesis) in cell cycle ❗️ ❕
1. Interphase
- There are actually three phases in interphase (G1 phase, S phase and G2 phase)
G1 phase
- Cellular synthesis occurred in G1 phase including : protein synthesis, RNA synthesis, ATP synthesis and organelles synthesis.
- Cell growth occurred in G1 phase through increasing the quantity of cytoplasm.
- To summarise, G1 phase is the time cell increase cellular content and size.
S phase
- DNA content of cell duplicated in S phase through DNA replication.
G2 phase
- Cellular synthesis occurred in G2 phase including : histone and spindle protein synthesis, enhancing energy storage for cell division through ATP synthesis, organelles replication.
- To summarise, G1 phase is the time cell prepare for nuclear division (mitosis/meiosis).
In HKDSE Biology examination, you don't have to divide interphase into G1 phase, S phase and G2 phase ❗️ ❕Just remember interphase is the time cell growth and DNA duplicated to prepare for nuclear divison (mitosis/meiosis) ❗️ ❕
2. Nuclear division
The details of mitosis and meiosis will be discussed in the coming blogs 🤩
3. Cytokinesis
- Cytoplasm and organelles are equally distributed to each daughter cell in cytokinesis.
👆🏻This photo showing cytokinesis occurred in animal cell.
- In cytokinesis of animal cell, cytokinetic furrow will be formed and separating two cell via pinching off .
👆🏻This photo showing cytokinesis occurred in plant cell.
- In cytokinesis of plant cell, cell plate will be formed and separating two cell via growing between to nucleus towards the cell wall.
That's the end of this topic 👏🏻
References
- Thomas, B. & Chris, H. (2013) Hong Kong DSE Biology Critical Guide. Yellowreef Limited.
- The Cell Cycle - Phases - Mitosis - Regulation. (n.d.). Retrieved from https://teachmephysiology.com/basics/cell-growth-death/cell-cycle/
- Editors, B. D. (2019, October 5). Cytokinesis. Retrieved from https://biologydictionary.net/cytokinesis/