1. Which of the following are roles of stem cells o m) 5w;nn4rrwin living 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 differentiato w6+tr z-u)awed cells in an individual plant such as the golden barrel cactusbarrel (Echo)uatzr6w- w+ inocactus grusonii) shown in the image?

  3. What are essential ys a ot7 (l 3ra/yvi4.qg;1dlhproperties of stem cells?

  4. What is the cause of stem cells differentiating 0 qcta v2mol( 1)chwc b2cx0,hjlm5,kalong different pathways to produce a variety of di,m0ohv )tl012a 5j2, mqlcwxchbck c(fferentiated cells?

a. Use the graph to est-h4iq. ejbipu mutqp80wl6g *se.6j4 imate the volume of a liver cell.

b. The image is of cardiac 5 zdjr, 9fy7/oynsm10gzh.a+ uz gz:x muscle.

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 why a human ovum has specialized to have a large volumend7brn*+ 7dar.

d. Estimate the mean length of a cell with a volume of 1000 µm3 us+dn6 (n-uhjl-mr/ guqing the trend line on the 6hn g+rd lmnqu -(uj-/graph.

e. The horizontal error bars represe 7u;d76vbm s1digsco5nt standard deviation. Suggest what the standard d6d1bis7o; mu7v 5dcg seviation signifies.

f. Simplified models are commonly used to investigate scientific ph1ukb :u4n x,wienomena.
Outline the limitations in the use of a sphere to model surface area to volume ratio in cells.

6. Using examples from hu1xfczm1 3)a -)f(x k au6afgdrman tissues, distinguish between pluripotent, totipotent and multipo6a(z) xf1rfd3u a-cfa1kx)mg tent stem cells.

7. Explain the role of(ft74*4m *zpzv)igvb7 rqps q stem cells in a multicellular organism.

(a) Explain why a large surface area to vol (ejikwx2.n,k,o f 8doume ratio can increase cell efficiency.o2,i8 doekkj,nxw( f.

(b) Describe, using two specific examples, how 7v0a(0lru l uw9)ktpq) hqbu6cell adaptation can increase surface area to volume ratio in a specialised cell.0u h7uua)l )(bkt6 qplw9vq0r

(c) Many tissues found+ wxou y:-j/xe in plants are compound tissues, such as phloem tissue shown in the image. Phloem tissue transports organic nutrients from their site of production (often, the leaf) to sites of storage or metabolism (often flowers or rootwojxex-+:/yu s)

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