Stem Cells

Question 1

What are stem cells?

Answer 1

can divide and differentiate to become different types of cells
can divide for all of the organisms lifetime

Question 2

How many types of stem cells are there and what are they?

Answer 2

totipotent
pluripotent
multipotent
unipotent

Question 3

What is totipotent?

Answer 3

stem cells that can differentiate into any type of specialised cell

-very early mammalium embroyos
can form placental cells

Question 4

What is pluripotent?

Answer 4

stem cells that can differentiate into many types of specialised cell

• embroyos but cant make placental cells

Question 5

What is multipotent?

Answer 5

stem cells that can differentiate into a few types of specialised cells

e.g. bone marrow -> rbc & wbc

Question 6

What is unipotent?

Answer 6

stem cells that can differentiate into one type of specialised cell

e.g. heart unipotent cells can make cardiomycetes only

Question 7

Describe cell specialisation

Answer 7

all cells contain 100% of an organisms DNA

conditions within cells control which genes are expressed (translated + transcribed) into proteins which change internal enviroment of the cell and affect the expression of other genes

then cells become specialised