Unit 1 Topic 4 Flashcards
(25 cards)
What is differentiation?
the process by which cells or tissues undergo a change towards a more specialised function
What are the levels of organisation in order?
cell -> tissues -> organs -> organ systems
Where does growth take place in a plant
meristems
what are meristems
regions of unspecialised cells in plants that can divide/ self-renew and/or differentiate
what is the process by which cells divide
unspecialised cells divide rapidly by mitosis to differentiate and form new plant tissues
where are apical meristems located
at the tips of the roots and shoots in a plant
what meristems are located only at the tips of the roots and shoots of a plant
apical meristems
what are stem cells
unspecialised cells
what can stem cells do
self-renew
differentiate
what special characteristics that stem cells have make them different to other body cells?
•undifferentiated, allowing them to divide and maintain a supply of stem cells for the body
•found in all multicellular organisms
•self-renewing and can differentiate
what are the two types of stem cells
embryonic stem cells
tissue (adult) stem cells
where are embryonic stem cells derived from?
embryos at the blastocyst stage
how can embryonic stem cells be described?
pluripotent
What type of stem cells are pluripotent and what does it mean?
embryonic stem cells
pluripotent means they can differentiate into many different types of cells
What are tissue stem cells involved in?
the growth, repair and renewal of the cells found in that tissue
How can tissue stem cells be described?
Multipotent
What type of stem cells are multipotent and what does it mean
tissue stem cells
multipotent means they can differentiate into only certain types of cells
where can tissue stem cells be found?
brain
bone marrow
peripheral blood
blood vessels
skeletal muscle
skin
What is cellular differentiation
the process by which a cell develops more specialised functions by expressing the genes characteristic for that type of cell
what is cellular differentiation the result of?
gene expression
Why don’t all cells complete the process of differentiation and pause at the stage where they can still undergo duplication?
it allows them to generate replacement cells which may die or be damaged- it allows for growth and repair. These cells are known as tissue stem cells
Give examples of therapeutic uses of stem cells?
Skin: patients with serious burns can be treated using a technique which grows new skin in the lab from skin stem cells
Blood: bone marrow transplants have been carried out for many years as a treatment for diseases such as leukaemia and other blood disorders
Cornea: corneal stem cells can be transplanted onto the diseases cornea to repair it
What can research involving stem cells allow scientists to find out?
Stem cell research allows scientists to discover more info about key cell processes such as growth, differentiation and gene regulation. Stem cells can also be used to study how diseases develop. Stem cells may be a viable alternative to animals for testing new drugs in the future
Give an ethical issue of stem cells
some people believe the destruction of the blastocyst is unethical
