Specialised Cells Flashcards
What is differentiation
Genes (such as DNA) inside the nucleus are switched on and off causing the cell to make different proteins. This leads to different structures being formed.
What is a specialised cell.
A cell that is adapted to perform a certain function
What is the function of a sperm cell.
To carry the fathers genes and fertilise an egg to make a baby.
What adaptations do a sperm cell have to help it carry out its function.
- Tail is long and it rotates to propel the cell to search for the egg.
- Lots of mitochondria to provide energy for a long distance swim.
- Head contains nucleus with half the fathers DNA (chromosomes) so the baby is healthy.
What is the function of a nerve cell?
To conduct electrical pulses to communicate with other cells muscles or glands.
What adaptations help a nerve cell to carry out its functions
Elongated axon to reach and transmit impulses directly between cells that are far apart.
Myelin sheath insulates the axon to speed up impulse transmission.
Lot’s of dendrites to receive impulses from other cells
What is the function of a muscle cell
To contract and move.
Adaptations that help a muscle cell to carry out its function?
Lot’s of mitochondria to release energy from respiration for contraction.
Lot’s of ribosomes to make protien filaments to slide over each other for contraction.
More than one nucleus per cell to make sure contraction is in unison.
What is the function of a root hair cell
To absorb water and minerals from the soil
Adaptations that help a root hair cell carry out it’s function.
Large surface area for molecules to move into the plant at a faster rate.
No chloroplast as it is underground and so there is more room for other structures.
Large vacuole to maintain shape and remove water from cytoplasm to maintain a concentration gradient for osmosis
What is the function of a xylem cell.
To carry and transport water minerals from the soil and leaves.
Adaptations that help xylem carry out there function
Living when formed but then die and lose contents to create hollow tubes to allow water to flow uninterrupted.
A special chemical called lignin builds up cell wall to make it extra strong to withstand water pressure.
What is the function of phloem
To carry sugars made in leaves up and down plant to other areas
Adaptations that help phloem complete there function.
Cell wall between cells break down to form sieve plates for movement of dissolved sugars.
Most internal structures are lost but cell is still alive. They are kept alive by companion cells which have lots of mitochondria that provides energy to move sugars up and down
What is stage one of the cell cycle.
Growth and replication of sub cellular structures
What is stage 2 of the cell cycle
Mitosis (nuclear division)