Cellular differentiation

Differentiation

The process of which a cell develops a more specialised function by expressing certain genes to produce proteins characteristic for that type of cell

Meristems in plants

This is a group of unspecialised cells that divide repeatedly by mitosis in plants

Where are meristems found in plants?

In the shoot tips and roots of plants

What do all multicellular organisms start life as?

A fertilised zygote

How is an embryo formed?

When a zygote divides repeatedly by mitosis

What do embryos have the potential to do?

They have the potential to differentiate into any type of cell because all of their genes can be switched on

Stem cells

Unspecialised somatic cells in animals that can divide to make copies of themselves (self-renew) or can differentiate into one or more specialised cells (this is irreversible)

Somatic cells

Cells that aren’t sex cells (gametes)

What happens when a cell becomes differentiated?

It expresses the certain genes that code for the proteins specific to the function of the particular cell

Where are the two types of stem cells found in humans?

In adult tissue cells and embryonic cells

Embryonic stem cells

A stem cell with the capability to switch on any gene

Pluripotent

Stem cells that can differentiate into any type of cell

What type of stem cell is pluripotent?

Embryonic stem cells

Adult tissue stem cells

A stem cell with the capability to switch on a limited range of genes, used for growth, repair, and the renewal of damaged cells or tissues

Multipotent

Stem cells that can differentiate into a limited range of cells

What type of stem cell is multipotent?

Adult tissue stem cells

What two things are stem cells used for in research?

Drug testing and as model cells for studying diseases

What are stem cells used for in therapy?

The repair of damaged or diseased organs or tissues

What are two examples of therapeutic uses of stem cells?

Corneal transplants and skin grafts

What are two ethical issues regarding the use of stem cells?

Against - embryos are destroyed

For - less animal testing

What happens when an embryonic stem cell is removed from its host?

The embryo is destroyed and is no longer viable to become a potential life

How do somatic cells inherit characteristics?

Mitosis