differentiation Flashcards
as each new cell is formed, it grows and matures and then becomes specialised to carry out particular function, what is the process of specialisation called
differentiation
animal cells : early stage
plant cells : throughout life
what are some examples of differentiation
nerve cells
kidney cells
bone cells
muscle cells
all contain same genetic material but specialised to carry out different functions
how are multicellular cells organised
cells –> tissues –> organs –> organ system –> organisms
how is erythrocyte specialised?
biconcave shape –> increase surface area to volume ratio for diffusion + increase cell flexibility to fir through narrow capillaries
no nucleus –> more space to hold haemoglobin to increase oxygen transport
made from stem cells in the bone marrow
how is neutrophil specialised?
white blood cell
lobed nucleus, granular cytoplasm –> flexible enable them to surround pathogens and engulf them
contain lysosomes filled with hydrolytic enzymes
made from stem cells in the bone marrow
how are sperm cells specialised?
flagellum contains many mitochondria –> release energy for locomotion, enable sperm cell to move towards the egg cell
acrosome in head of cell contains digestive enzymes –> digest the wall of the egg cell so sperm can penetrate and fertilise the egg cell
how are palisade cells specialised?
located in mesophyll tissue layer
rectangular, tightly packed contains many chloroplast –> absorb and maximise light energy for photosynthesis
thin cell walls –> reduce diffusion distance of carbon dioxide
how are root hair cells specialised?
on surface of roots
long projections –> increase surface area for osmosis of water + active transport of minerals ions
thin cell wall –> reduce diffusion distance
how are guard cells specialised?
flexible walls [on one side] –> cells bending when turgid to open stomata + closing when flaccid , helps control water loss by transpiration
define tissues
groups of cells working together to perform a function
what are epithelial tissues
composed of specialised cells that cover the inside and outside of structure within the body
how is squamous epithelial cells specialised?
a single layer of flat cells in contact with the basement membrane of the epithelium –> short diffusion distacnce
form the lining of the lungs
how is ciliated epithelial cells specialised?
hair-like projections –> sway to move substances {e.g. mucus out of lungs/egg in oviduct}
how is goblet cells specialised?
located within the epithelium
cells release mucus –> trap molecules {trapping dust in trachea}
how is the cartilage specialised?
connective tissue, firm and flexible, located in outer ear, nose and end of bones
provide structural support
prevents bones from rubbing together which would damage them
made up of elastin and collagen fibres and chondrocyte cells within an extracellular matrix
