Stem cells and organisation

Question 1

What is a specialised cell?

Answer 1

Cells with certain features that allow them to carry out a particular function

Question 2

What are examples of each level of organisation in an organism?

Answer 2

Specialised cells = erythrocytes, neutrophils, and palisade cells
Tissues = epithelium, cartilage, and xylem tissue
Organs = stomach, pancreas, and leaf
Organ systems = CV system, digestive system, and root system

Question 3

What are the key features of stem cells?

Answer 3

• can divide by mitosis to produce more undifferentiated cells
• can differentiate into specialised cells

Question 4

How are stem cells grouped into categories?

Answer 4

Potency = ability to differentiate into different cell types

more cell types a stem cell can differentiate into the greater it’s potency

Question 5

What are the 4 key types of stem cells?

Answer 5

Totipotent = can differentiate into any cell type and form whole organisms

Pluripotent = can differentiate into most cell types but can’t go on to form whole organisms

Multipotent = can only differentiate into few different cell types

Unipotent = can only differentiate into one type of cell

Question 6

Describe the location and potency of embryonic stem cells?

Answer 6

Location = early stages of embryo development where they can differentiate into cells to form a foetus.

Potency = 1st few embryo divisions the stem cells are totipotent then after about 7 days cells become pluripotent

Question 7

Describe the location and potency of adult stem cells?

Answer 7

Location = some adult tissues where they can replace faulty cells

Potency = multipotent or unipotent

Question 8

Describe the location and potency of plant stem cells?

Answer 8

Location = meristematic tissue at the tips of the shoots and roots also tissue found between phloem and xylem tissues (vascular cambium)

Potency = pluripotent

Question 9

What are some other purposes of stem cells?

Answer 9

Drug testing = tested for toxicity and side effects before human testing

Studying organism development = scientists can find out how organisms grow and develop from a single cell

Disorder causes = scientists can identify when something goes wrong in an organism’s development