Stem cells

Question 1

Stem cells

Answer 1

Cells that are not specialised and are completed/divided by mitosis repeatedly, a process called proliferation.

Given the right conditions stem cells can differentiate into specialised cells.

Question 2

Differentiation

Answer 2

The process by which unspecialised cells like stem cells develop special characteristics to suit particular functions.

During differentiation specific genes are activated causing the cells to produce proteins that shape its role in the body.

Question 3

Specialised cell

Answer 3

A cell that has developed certain characteristics to perform a specific function/task within an organism. Most specialised cells cannot divide.

-Neurons, muscle cells, liver cells, RBCs, WBCs

Question 4

What are the 3 stages of stem cell differentiation

Answer 4

• Totipotent
• Pluripotent
• Multipotent

Question 5

Step 1: Totipotent stem cells

Answer 5

A type of stem cell that has the potential to become any type of cell that is necessary for embryonic development (embryo and embryonic membranes).

Ex - Zygote

Question 6

Step 2: Pluripotent stem cells

Answer 6

Stem cells that can develop into any cell type of the body but cannot form tissues such as the placenta.

They are formed from Totipotent Stem cells.

Ex: Inner cell mass of the blastocyst

Ex: Embryonic stem cells

Question 7

Step 3: Multipotent stem cells

Answer 7

Stem cells that can develop into a limited range of cell types within a specific tissue or organ system.

Arise from pluripotent stem cells after germ layers form.

Examples:
Hematopoietic stem cells → RBCs, WBCs, platelets

Mesenchymal stem cells → bone, cartilage, fat

Adult stem cells in various tissues

• Cannot become certain cells

Question 8

4 types of Embryonic membranes

Answer 8

• Yolk sac
• Amnion
• Allantois
• Chorion