Stem cells Flashcards
what are the stem cells is plants called?
Meristems
What is cambium?
cells that can differentiate into xylem and phloem
It is an example of a meristem.
Basic structure of xylem
Dead, no cytoplasm, all space used for transport of water/minerals. strong cellulose cell walls and lignin support the xylem vessels, pits allow some lateral movement of water and support the natural movement of water, joined end to end.
Basic structure of phloem
Sieve tube element sieve plate, thin cytoplasm wall, few organelles so easy to transport sugars
companion cell contains organelles the phloem needs to live, mitochondria-provide energy,
Basic structure of palisade leaf cells
lots of chloroplasts-photosynthesis, vacuole-stores waste/sugars, long-large surface area, thin-lots can fit in a small space.
what are erythrocytes?
Red blood cells
what is the scientific name for red blood cells?
erythrocytes
what are neutrophils?
white blood cells
what is the scientific name for white blood cells?
neutrophils
what are stem cells?
undifferentiated cells that have the potential to become specialised.
what is differentiation?
the process in which cells differentiate and become specialised.
what is the structure of erythrocytes?
Biconcave-larger surface area. lots of haemoglobin-works reversibly with oxygen and CO2. No organelles-more space for haemoglobin.
what is the structure of neutrophils?
phagocytic- contain lysosomes, granular cytoplasm, multilobed nucleus.
what is the structure of sperm cells?
Haploid nucleus, helical mitochondria, undulipodium, acrosome contains enzymes to digest the eggs wall.
what is the structure of squamous epithelial cells?
have a basement membrane, very thin, allows rapid diffusion (shirt diffusion pathway)
what is the structure of ciliated epithelial cells?
have a basement membrane, cilia waft substances away, mucus traps some substances. Goblet cells produce the mucus.
what is special about embryonic stem cells?
they are totipotent (can differentiate into any cell)
what does totipotent mean?
potential to differentiate into any type of cell.
what does pluripotent mean?
potential to differentiate into any type of tissue
what does multipotent mean?
potential to differentiate into any cells within a certain tissue.
what does unipotent mean?
potential to differentiate into only one type of cell
which cells are totipotent?
embryonic stem cells
which cells are pluripotent?
umbilical cord
Meristematic
which cells are multipotent?
Adult (Bone marrow)
Vascular (root and stem in plants)
Which cells are unipotent?
Adult (skin)
what ethical reasons are there against stem cell research?
Embryo is killed to produce cells.
Human life is sacred so shouldn’t be destroyed.
Human rights of embryo are violated
May increase risk of tumour formation
what uses do stem cells have in treating diseases?
Can replace damaged tissues- treat Parkinson’s (embyonic)
Blood diseases (leukemia) (bone marrow/umbilical)
Skin graft (skin)
stem cell therapy (meristematic)
What are the arguments for using embryonic stem cells?
Small number of embryos can make lots of cells for patients
Embryos would be destroyed regardless
No need for insulin injections
Reduce likelihood of rejection compared to injection
No issues with donor waiting list
