1. Which of the following are roles of stem cells in living ors pgiyg 3a1u*)ganisms?
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 differe m-68(4zxdbud goct5r:pe l.untiated cells in an individual plant such as the golden ba-8te: mddo .u6g5 lpuxzbcr(4rrel cactusbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties of q/z:yb mu v9baw m-k5o h1m6q:stem cells?

  4. What is the cause of stem cells differentiating along different t i9yh:cq7f2lb63bt5 *q jrgb pathways to produce a variety of diffeg*7bi6t9 q2h3jfl5b yr: q tcbrentiated cells?

a. Use the graph to estimate the volu-t nudp8y3s8, vq-x r0ppr7hj me of a liver cell.

b. The image is of cardiac muscg;4jgjey kr hr/ 2s5i*le.

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 specia+q9v-cm z1 do1nfs kv9lized to have a large volume.

d. Estimate the mean length of a au1s l -at)pm xs -u2m;ft.5;agw.nfucell with a volume of 1000 µm3 using the trend line on tha1;-.m.tsw )m5ufugtanp2x;su afl -e graph.

e. The horizontal error bars represent standard deviavi6 r98tzoz f5tion. Suggest what the standard deviation68z9zf io5 rvt signifies.

f. Simplified models are commonly used to investigate scientific pheno mh 0m438dai-in;tnfemena.
Outline the limitations in the use of a sphere to model surface area to volume ratio in cells.

6. Using examples from hu(0pqu72b vxxa4fq:jj i 7 claik:1z *kman tissues, distinguish between pluripotent, totipotent and multipotent stem v*a(17uki lp4iaz0 cqk xfxq:2bj :j7cells.

7. Explain the role of stem cells in a multicellular organism.42r6 uwm 7jezf6 dz,p goe2da4

(a) Explain why a large surface area to volume ratio can in5dk;(sk)ip4:g i z ca 5bl4qwacrease cell efficiency.kl5p w az(bi :q said)kg445;c

(b) Describe, using two specific examples, hvx(58 zx xrhhupt-.1 8 mj;hshow cell adaptation can increase surfrt 1 hx 8vh-shxu;j(.8mxp5 hzace area to volume ratio in a specialised cell.

(c) Many tissues found in plants are compound tissues, suc7p*wnv sspc /ti,9s/kh 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 flowersvsk / p,/isnwt *97spc 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