Cell Specialisation Flashcards
What Is differentiation?
When cells gain certain features needed for their purpose
What are the features of a xylem cell?
- no contents, just a column of water
- line up in tubes to make xylem vessels
- cells are dead
- used to transport water and mineral ions
What are the features of a phloem cell?
- very few organelles
- joined end to end to make a tube
- contain perforated sieve plates
- transport dissolved sugars and amino acids
What are the features of a cone cell?
- contains visual pigment to allow colour vision
- usually links to a nerve cell so we can respond to visual stimuli
- contains lots of mitochondria to release energy
What are the features of a cone cell?
- contains visual pigment to allow colour vision
- usually links to a nerve cell so we can respond to visual stimuli
- contains lots of mitochondria to release energy
What are the features of an egg cell (ovum)?
- contains nucleus with half number of chromosomes, so when fused with sperm there is full amount
- cell membrane changes after fertilisation so only one cell can enter
- cytoplasm contains lots of nutrients for growth of early embryo
- is a gamete used in sexual reproduction that passes on mother’s genes
What are the features of a sperm cell?
- nucleus in the head has half number of chromosomes so when fused with ovum there is full amount
- acrosome in the head has digestive enzymes to break down outer layer of ovum
- mitochondria releases energy for flagellum to rotate for movement
- is a gamete used in sexual reproduction that passes on Father’s genes
What are the features of a root hair cell?
- has a projection to Inc. SA to Inc. Water uptake rate
- thinner walls let water move through easily
- lots of mitochondria for energy for active transport of mineral ions
- no chloroplasts
What are the features of a fat cell?
- contains a fat store which can be broken down to release energy
- can increase size to store more fat when needed
- small cytoplasm so more space for fat storage
- acts as energy store
What are the features of a ciliated epithelial cell?
- pathogen trapping mucus is made by goblet cells
- contain cilia that waft mucus
- many mitochondria for energy for wafting
- line airways to protect from pathogens
What are the features of an RBC?
- no nucleus so more space for oxygen
- large SA to maximising oxygen intake
- transports oxygen and carbon dioxide around body
What are the features of a muscle cell?
- contains filaments that can contract
- many mitochondria to provide energy for contraction
- cells are elongated and fuse together to allow contraction over a longer area
- contraction for movement
What are the features of a guard cell?
- banana shaped, found in pairs
- change shape to open stomata to allow gas exchange in the leaves
What are the features of a palisade cell?
- regular box like shape to pack tightly together to maximise photosynthesis
- many chloroplasts
- most chloroplasts at top of cell where there is more light
What are the features of a nerve cell?
- long and thin to carry electrical impulses long distances around the body
- long bit called axon
- mtiple points of connection at each end
- lots of mitochondria for energy
Qhat are stem cells?
An undifferentiated cell capable of slef renewal via mitosis to produce more stem cells or differentiate into specialised cells
Where are embryonic stem cells found and what can the differentiate into?
- found in 3-5 day old embryo
- can differentiate into any specialised cell
Where are adult stem cells found and what can the differentiate into?
Found in many places in adults, but mainly bone marrow
Can only specialise into the type of tissue from where they’re found.
Where are umbilical cord stem cells found and what can the differentiate into?
Found in umbilical cord
Can differentiate into blood cells, can treat blood disorders of the child it was attached to
How does therapeutic stem cell cloning work?
- nucleus is removed from egg cell
- nucleus from patients body cell is removed and fused with egg cell
- very small electric shock causes division
- After 3-5 days you can extract stem cells
Why are some people against using embryonic and therapeutic stem cells?
They consider it unethical
It is also very expensive
Where are plant stem cells found?
Tips of roots and shoots in a layer called the meristem
These can differentiate into any plant cell
