2.6 - cell division, cell diversity + cellular organisation

Question 1

what are stem cells?

Answer 1

undifferentiated cells which are genetically identical and have the ability to develop into any of the various kinds of cells

Question 2

what uses do stem cells have in research and medicine?

Answer 2

• repair of damaged tissues
• treatment of neurological disorders such as Parkinson’s and Alzheimer’s
• studying development

Question 3

what is differentiation and give example?

Answer 3

• process by which a cell specialised to carry out a particular function
• for example: stem cells in bone marrow differentiate into erythrocytes (red blood cells) and neutrophils (white blood cells)

Question 4

describe differentiation in plants?

Answer 4

• they retain their ability to differentiate into different types of cells throughout their life
• division of plant cells occurs at a high rate in meristems, dividing meristem cells are known
  as the cambium and make xylem and phloem tissue

Question 5

four examples of specialised cells?

Answer 5

sperm, palisade, root hair, guard

Question 6

what is a tissue?

Answer 6

group of cells working together to perform a common function

Question 7

what is an organ?

Answer 7

group of tissues working together to perform a wider function

Question 8

what is an organ system?

Answer 8

a group of organs that work together to perform an essential life function

Question 9

describe phloem?

Answer 9

• tubes made of living cells which are involved in translocation
• have elongated cells and sieve plates
• have metabolically active companion cells next to sieve plates that are involved in mediating movement of photosynthesis products up and down in tubes

Question 10

describe xylem?

Answer 10

• transport water and minerals and provide structural support
• long cylinders made of dead tissue with open ends
• thickened with lignin
• consist of parenchyma, fibres and vessels

Question 11

describe epithelial tissue?

Answer 11

• sheet of cells that serves as a lining
• two types: squamous and ciliated
• squamous are smooth, flat + thin, fitting closely together to create smooth surface like lining of blood vessels and cheeks
• ciliated is composed of column shaped cells containing cilia which form lining of structures like trachea and bronchi, cilia move together to move mucus produced by goblet cells along

Question 12

what is connective tissue?

Answer 12

• involved in providing support and holding various structures together
• examples include cartilage and bone

Question 13

what is muscle tissue specialised for?

Answer 13

movement through contraction

Question 14

what is nervous tissue specialised for?

Answer 14

impulse conduction