Topic 8- totipotent stem cells

Question 1

What is a stem cell?

Answer 1

a cell that can divide by mitosis an unlimited number of times

Question 2

What is differentiation?

Answer 2

Each new cell that is produced when a stem cell divides has the potential to remain a stem cell or to develop into a specialised cell such as a blood cell or a muscle cell

Question 3

Define potency

Answer 3

ability of stem cells to differentiate into more specialised cell types

Question 4

What are the 3 types of potency

Answer 4

-Totipotency
-Pluripotency
-Multipotency

Question 5

Which type of cells can divide and produce any type of body cell?

Answer 5

Totipotent (also known as embryonic)

Question 6

Where do totipotent stem cells exist for a limited amount of time?

Answer 6

-in early mammalian embryos
- in extra-embryonic cells (the cells that make up the placenta)

Question 7

The zygote is formed when a sperm cell fertilises an egg cell. What type of cell is this?

Answer 7

Totipotent

Question 8

What type of cells are the embryonic cells up to the 16-cell stage (morula) of human embryo development?

Answer 8

Totipotent

Question 9

Describe the process of specialisation

Answer 9

-To begin with, totipotent cells in the embryo are unspecialised
-During development, totipotent cells begin to translate only part of their DNA, which results in cell specialisation
-specialised cells then form tissues (no longer considered unspecialised)

Question 10

Can cells lose their ability to differentiate later in development?

Answer 10

Yes