1. Which of the following are roles of stem cells in livinvdh+ccv-jmg*e 80 bi-g organisms?
I. Growth of new organs.
II. Replacement of damaged cells.
III. Production of cells which could differentiate.
IV. Produce new stem cells by mitosis.

  2. Which of the following correctly describe the t2s zjx8847y,am g mhqdifferentiated cells in an individual plant such as the golden barrel cacthx4y a7zt 8s,gm qj82musbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties odgf6,2 ,e6gagrjd aau7dt q. 3f stem cells?

  4. What is the cause of stem cells diffe6nx 2mvfkq0+iz* yss5rentiating along different pathways to produce a variety of differentiated c+i2 6n*ks0xmz qs5f vyells?

a. Use the graph to estimate the voludw2 s.rpu2 bz;me of a liver cell.

b. The image is of cardiac muscaj2+.rv ge:m ele.

Cardiac muscle cells have a mean length of 100 µm and an estimated volume of 8000 µm3.
Explain why the cell length and volume ratios are not constant for all cell types.

c. Suggest one reason;i emvfm;zb5.2 bnug 3 why a human ovum has specialized to have a large volume.

d. Estimate the mean length ofh7.m i oq(-iq hvh79rk a cell with a volume of 1000 µm3 using the trend line on7roqihh hq.kvi(79m - the graph.

e. The horizontal error)d ym6-h58 dbcrm7ivcg, fbt; bars represent standard deviation. Suggest what the standard de5rctdfvb6ch m 8y,bd ;7 g)-imviation signifies.

f. Simplified models are commonly used to investigate scientific phenomenasv, 2e8nef+uyui w.s 5.
Outline the limitations in the use of a sphere to model surface area to volume ratio in cells.

6. Using examples from human tissues, distinguish between pluripotent, totip. 5b/s x,k6ra ; ysn9utzpqoa.otent and multipotent stematq ux9ss rn ,6/a. ;kzboyp.5 cells.

7. Explain the role of stem cells in or+)1mc, q9gr qai6kua multicellular organism.

(a) Explain why a large y/8mqi+ltv 3e surface area to volume ratio can increase cell efficienc m38t/lveyq+iy.

(b) Describe, using two specif1o ss+rn ilk zx( 5c,smll99y)ic examples, how cell adaptation can increase surface area to volume ratil +k)1cislz5l9 ( moxy9ssr,no in a specialised cell.

(c) Many tissues found in plants are compound tissues, such as4; zva 04y0wr pnqnal/ phloem tissue shown in the image. Phloem tissue transports organic nutrients from their site of prod y44/0q n;na0pawlrzv uction (often, the leaf) to sites of storage or metabolism (often flowers or roots)

Compound tissues consist of several different cell types, simple tissues of only one cell type.
Outline why many tissues in multicellular organisms have more than one cell type in the tissue