Thursday, April 8, 2010
8th April: Root Hair Cells
A Report by: Karan Sarat, Yuzhe Ng, Zheng Jie, Lionel Lim, Darryl Lam & Jasper Phang
(a) What are the Organelles Found In The Cell?
They are the: nucleus, cytoplasm, plasma membrane, cell wall and vacuole. As you can see the root hair cell has fewer organelles than most other cells.
(b) List The Structural Features Of The Cell?
They have in comparison to other cell a large surface area which helps them collect water. They are found near the tip of the roots and appear like hairs. The whole structure is quite delicate. It can only survive for a few days and don't properly develop into a proper hair.
(c) What Are The Functions Of These Organelles?
Nucleus: the nucleus controls all the activities taking place in the cell and it is also responsible for cell division.
Cytoplasm: The cytoplasm plays a mechanical role, i.e. (example) to maintain the shape, the consistency of the cell and to provide suspension to the organelles.
Plasma membrane/cell membrane: The plasma membrane will allow certain substances to cross it but not others
Cell wall: A major function of the cell wall is to act as a pressure vessel, preventing over-expansion when water enters the cell
Vacuole: produces turgor pressure against cell wall for support
- stores water and various chemicals
- may store insoluble wastes
(d)Why are these functions of the organelles important to the living cell?
Nucleus: The nucleus:It contains DNA,in other words,deoxyribose acid; it is therefore the 'brain' of the cell because DNA contains "instructions" needed for the cell to reproduce and do other functions.Cells without a nucleus can survive for short periods,but cannot survive for long-term periods
Cell membrane: The cell membrane is like the skin of the cell.It also gives the cell its shape,and ,like a skin,prevents certain substance from entering it.
Cytoplasm: Cytoplasm can be said as the material that lies within the cell membrane,contains a lot of water, and the other organelles of the cells. It provides a platform upon which they can operate within the cell.So,without the cytoplasm,the cell will dry up and the organelles cannot operate.
The cell wall provides the most significant difference between plant cells and other cells.It is rigid and gives the plant a definite shape. The cell wall is the reason for the difference between plant and animal cell functions. Because the plant has evolved this rigid structure, they have lost the opportunity to develop nervous systems, immune systems, and most importantly, mobility.
Plant cells use their vacuoles for storing nutrients,and function as a storage organelle. In a sense, the vacuole can be regarded as equivalent to the extra cellular space of animals. The simple space-filling function of the vacuole is of great importance to plants, which capture energy from the sun rather than move to capture food.