specialised cells and their functions Flashcards
how do cells specialise
cells specialise by undergoing differentiation
what is differentiation
a process that involves the cell gaining new sub-cellular structures in order for it to be suited to its role
when does cell differentiation occur
cells can either differentiate once vary on or have the ability to differentiate their whole life
what are stem cells
stem cells are the cells that have the ability to differentiate their whole life
what is different about cell differentiation in plants and animals
in animals, most cells only differentiate once, but in plants many cells retain the ability
what is the sperm cell specialised to do
sperm cells are specialised to carry the males dna to the egg cell (ovum) for successful reproduction
how is the sperm cells shape specialised towards its function
the sperm cell has a streamlined head and long tail to aid swimming
why does the sperm cell have a lot of mitochondria
lots of mitochondria (where respiration happens) supplies the energy to allow the cell to move
what is the acrosome
the acrosome is the top of the sperm cells head has digestive enzymes which break down the outer layers of membrane of the egg cell
what is different about the nucleus of a sperm cell
the sperm cell has a haploid nucleus, which simply means that it has 23 chromosomes rather than the 46 that most other body cells have
what is the egg cell specialised to do
egg cells are specialised to accept a single sperm cell and develop into an embryo
how is the egg cells membrane specialised to its function
the egg cell is surrounded by a special cell membrane which can only accept one sperm cell during fertilisation and becomes impermeable following this
what is the function of the mitochondria in the egg cell
lots of mitochondria works as an energy source forts he developing embryo
how does the size of the egg cell contribute to its function
the large size and abundant amount of cytoplasm allows quick repeat division as the embryo grows
what are ciliated epithelial cells specialised to do
ciliated epithelial cells are specialised to waft bacteria (trapped by mucus) to the stomach
how do cili contribute to the ciliated epithelial cells function
cilia are long, hair-like structures which waft bacteria trapped by sticky mucus (produced by near by goblet cells) down to the stomach where they are killed by the stomach acid.
what is the purpose of the cilia wafting bacteria tot he stomach
the bacteria is killed by the stomach acid which is one of the ways our body protects against illnesses
what are root hair cells specialised to do
root hair cells are specialised to take up water by osmosis and mineral ions by active transport from the soil as they are found in the tips of roots
what does the surface area mean in a root hair cell
having a large surface area due to root hairs means more water can move in
what do vacuoles mean in a root hair cell
the large permanent vacuole affects the speed of movement of water from the soil to cell
what do mitochondria contribute to a root hair cell
mitochondria provide energy from respiration for the active transport of mineral ions into the root hair cell
what are xylem cells specialised to do
xylem cells are specialised to transport water and mineral ions up the plant from the roots to the shoots
what is lignin and how does it contribute to xylem cells
lignin causes cells to die. they become hollow and are joined end-to-end to form a continuous tube so water and mineral ions can move through
how is lignin deposited
lignin is deposited in spirals which helps the cells withstand the pressure fr the movement of water
what are phloem cells specialised to do
phloem cells are specialised to carry the products of photosynthesis (food) to all parts of the plants
how do cell walls contribute to the function of the phloem cell
cell walls of each cell form structures called sieve plates when they break down, allowing the movement of substances from cell to cell
how is the energy for phloem cells provided
despite losing many sub cellular structures, the energy these cells need to be alive is supplied by the mitochondria of the companion cells
