B1- cell division Flashcards
how do chromosomes carry genetic information?
in DNA
how many chromosomes does the human body contain?
46
when do cells divide?
- when an organism grows
- an organism becomes damaged and needs to produce new cells
what are the two cells called in mitosis?
daughter cells
what are stem cells?
cells that have not yet undergone differentiation
what does an embryo develop from?
a fertilised egg
where can adult stem cells be found?
brain eyes blood heart liver bone marrow skin muscle
where does cell divion in plants occur?
meristems
what are cells of the circulatory system specialised to do?
Transport substances, defend the body, regulate temperature
what are cells of the excretory sytem specialised to do?
Remove waste products and unwanted substances, regulate the water content of the body
what are cells of the muscular system specialised to do?
bring about movement
what are cells of the nervous system specialised to do?
Respond to internal and external stimuli and conditions, carry messages for the body work as a coordinated whole
what are cells of the respiratory system specialised to do?
Deliver oxygen for respiration and remove waste
what are cells of the reproductive system specialised to do?
Bring about fertilisation to produce new offspring
what are cells of the skeletal system specialised to do?
to bring about movement, support and protect internal structures, produce blood cells, store and release calcium
what are palisade mesophyll cells specialised to do?
Carry out photosynthesis
what are spongy mesophyll cells specialised to do?
Allow gases to circulate for the exchange of gases between the leaf and the environment, carry out some photosynthesis
what are guard cells specialised to do?
Open and close to control the exchange of gases – carbon dioxide, water vapour and oxygen
what are sieve tubes specialised to do?
Transport products of photosynthesis, including sugars and amino acids, from the leaf to where they are needed
what are companion cells specialised to do?
Provide the energy required for transporting substances in sieve tubes
what are xylem vessels specialised to do?
Transport water and dissolved minerals from the roots, up the plant
what are meristems specialised to do?
produce new cells as they divide
when do they use human stem cells?
in type 1 diabetes
in cases of multiple sclerosis, which can lead to paralysis
in cases of spinal cord or brain injury, that have led to paralysis
