Unit 2- Stem Cells And Meristems

Question 0

What is the definition of stem cells?

Answer 0

The cell can divide to form new stem cells or can differentiate into a new specialised cell(s). The process is called DIFFERENTIATION.

Question 1

What is a specialised cell?

Answer 1

A specialised cell does a particular job in the body.Like blood, skin, muscle or nerve cells. Your body always needs new specialised cells. Most specialised cells cannot make copies of themselves.

Question 2

What are the two main types of stem cells?

Answer 2

1. Embryonic stem cells- Can make all different types of cell in your body.
2. Tissue stem cell- Can only make a few other types of cell. Blood stem cells only make other blood cells. Blood stem cells don’t make skin cells.

Question 3

Why are stem cells important?

Answer 3

⚫️ They make new cells to replace cells that die every day, and help you to grow.
⚫️They help repair damage, such as cuts and broken bones.

Question 4

Advantages of using embryonic stem cells.

Answer 4

• Curing debilitating diseases e.g parkisans,diabetes
• Embryos that would be thrown out are put to good use.
• Modelling disease and test medicines and drugs.
• Overall improving quality of life.

Question 5

Ethical arguments against embryonic stem cells.

Answer 5

Some people think an early embryo has the right to live.

Question 6

What is a meristem?

Answer 6

A region of cell division in a plant, producing non-specialised (undifferentiated) cells.

Question 7

Where are the meristems located?

Answer 7

Primary meristems are located at the shoot and root tips.

Question 8

How do meristems contribute to plant growth?

Answer 8

The unspecialised cells produced at the meristems have the potential to become any type of plant cell and they contribute to plant growth.

Question 9

What are the four key zones within a root apical (or tip) meristem that are essential for growth?

Answer 9

Region of differentiation- cells become specialised
Region of vacuolation&elongation-cells develop large vacuole and get longer
Meristem-Region of mitosis
Root cap-Protects the meristem

Question 10

What is mitotic index?

Answer 10

A measure of how quickly a tissue is growing. It’s a way of judging if a human tissue is cancerous, a high mitotic index can indicate a characteristic of cancerous cells.