1. Which of the following are roles of stem cells in living orgazfz5k4kh3dg8aq, ee da+ 79fknisms?
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 descrin9,.am vrdd,xs w;n5 tbe the differentiated cells in an individual plant such as the gv nsx.9mdrtd5 w;,, naolden barrel cactusbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties of st-mfn6a2v0s1 p jrr+f,; zqzje+ h;hhaem cells?

  4. What is the cause of stem cells differentiatinc q qva92s-1hd3u)x zhg along different pathways to produce a varie- ca923x vqu dhzh1)sqty of differentiated cells?

a. Use the graph to dbdqihbyt9 p5:* l ,a i3rh;l7estimate the volume of a liver cell.

b. The image is of cardiac muscle.py* q mjk3*:cp

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 r3en :6jdhj6i+)eetv7 wl s,sspecialized to have a large volume.

d. Estimate the mean length of ac m:pv65xrd54ll1 lq8 bu6hnq cell with a volume of 1000 µm3 using the trend line on the gq qm5:vb 568cl6xldh pnlru1 4raph.

e. The horizontal error bars represent standard deviation. Suggest:wq 02p :o pyo03yjmma what the standardaypyo :m2wpm0o03: j q deviation signifies.

f. Simplified models are commonly uses1 6ot1pp6gmvx)s we;d to investigate scientific phenomena.
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,iinj yk5qj5 l8yjzr;t0+2d 6b totipotent and multipotent j8;dt6lj5q b+nii 5k0yry z2j stem cells.

7. Explain the role of stem cells in a multicellular organism6fn*)d g7hy r .o6mlrw.

(a) Explain why a largi i*bbq4h,f b)+hy ;roe surface area to volume ratio can increase cell efficiency.y , )bfihb;r+b*4 hoqi

(b) Describe, using two spew o yrjt*z6:q:cific examples, how cell adaptation can increase surface area to volume*wrtoz6qj: y : ratio in a specialised cell.

(c) Many tissues found in plants are compound tissues, such as phloem w7sw+q p. k7yt734nxfs/ f ps 5sxeaj0tissue shown in the image. Phloem tissue transports organic.xsf7pa/fqx7sst05yn4w 3 jep k+7sw nutrients from their site of production (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