Specialisation in cells Flashcards
When do most animal cells differentiate?
in an early stage of development
When do most plant cells differentiate?
They retain the ability to differentiate throughout life
What happens when a cell differentiates?
It may change shape and different sub-cellular structures develop to let it carry out a specific function.
What are some examples of specialised animal cells
-Sperm cells
-Egg cells
-Nerve cells
-Muscle cells
What are features of a nerve cell?
- Many dendrites to connect to other nerve cells
- An axon to carry the impulse
- Nerve endings or synapses to pass impulses to other cells
- many mitochondria to transfer the energy needed to make the transmitter chemicals
-Nerve endings (synapses) are adapted to pass Impulses to other nerves or muscles with transmitter chemicals.
What are features of a muscle cell?
-Contain special proteins that slide over each other, making the fibres contract.
-Contain mitochondria to transfer the energy needed for the chemical reactions that take place as the cells contract and relax.
-They store glycogen, a chemical that can be broken down and used in cellular respiration by the mitochondria to transfer the energy needed for the fibres to contract.
What are the features of a sperm cell?
-A long flagellum (tail) to quickly move through the female reproductive system.
-The middle section is full of mitochondria, which transfer energy for the flagellum to work.
-The acrosome at the tip stores digestive enzymes for breaking down the outer layers of the egg.
-A large nucleus to pass on genetic information.
What are some examples of specialised plant cells?
-Root hair cells
-Photosynthetic cells
-Xylem cells
-Phloem cells
What are features of a root hair cell?
-Very high surface area for water to move into the cell
-Large permanent vacuole that speeds up movement of water by osmosis from soil across the cell.
-They have many mitochondria that transfer energy needed for active transport of mineral ions into the root hair cell.
What are features of a photosynthetic cell?
-Specialised green structures called chloroplasts containing chlorophyll that trap light needed for photosynthesis.
-Usually positioned in continuous layers in leaves and outer stem of a plant so they absorb as much light as possible.
-Have a large permanent vacuole to keep the cell rigid as a result of osmosis. This supports the stem and keeps the leaf spread out.
What are features of a xylem cell?
-Xylem cells are alive at first but quickly die and hollow tubes are left behind that allow water and mineral ions to move easily though them.
-Lignin builds up in spirals in the cell walls, keeping the xylem strong and able to support the stem as well as withstand the pressure of water moving up the plant.
What are features of a phloem cell
-Phloem cells carry food made from photosynthesis
-Phloem cells are alive.
-Cell walls break down into sieve plates which allow water carrying dissolved food to move up and down the plant freely to where it’s needed.
-Phloem cells lose a lot of their internal structures but are supported and kept alive by companion cells. These companion cells transfer the energy needed to move dissolved food up and down the plant in phloem.
