cell specialization

Question 1

macular degeneration

Answer 1

an age related eye disease caused when a part of the eye “macular” is damaged

Question 2

what happens in fertilization

Answer 2

• zygote begins dividing
• becomes a morula (solid ball of 16-32 cells)
• divides for 5-6 days until differentiates into a blastocyst (a hollow ball of cells that contains outer trophoblast and inner cell mass ICM)
• trophoblast develops into placenta
• ICM becomes the embryo

Question 3

stem cell potency

Answer 3

totipotent
pluripotent
multipotent
unipotent

Question 4

totipotent - example and what can differentiate into

Answer 4

cells of morula

can differentiate into any cell including placental cells - can give rise to an organism

Question 5

pluripotent

Answer 5

embryonic stem cells of the blastocyst

all body cells but not an organism

Question 6

multipotent

Answer 6

umbilical cord stem cells

a few closely related types of body cell

Question 7

unipotent

Answer 7

liver stem cell

only the associated cell type

Question 8

how many cells do humans contain

Answer 8

50-100 trillion size 7.5um to 150um

Question 9

stem cell niche

Answer 9

where the stem cells live and receive their instructions for differentiating from morphogen secreting cells

cell-to-cell interactions and cell-to-extracellular matrix interactions can determine how they differentiate

some cells may remain dormant if signalling molecules prevent genes from transcribing

Question 10

red blood cells

Answer 10

some of the smallest
no nucleus - more space for haemoglobin
highly flexible membrane
called erythrocytes

Question 11

bone marrow stem cell niche

Answer 11

blood cells
maintenance is important for the constant supply of blood cells through life