1. Which of the following are roles of stem cells in liv*/ ynjjc)t- vsing 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 differentiated cells in s 2(zd:rttcx,j q+4trp,(dpkan individual plant such 2d,:d, t+xprt t(rjqkp(cz4s as the golden barrel cactusbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties of stem cellsgogf5y-m20mqd, s- ux?

  4. What is the cause of stem cells differentiatinm.b5. fsyi8 mq nat9:tg along different pathways to produce a variety of differentiated tt .ms.8iy:bq5n 9fam cells?

a. Use the graph to estimate t4umir ,hleqp kv+:21;.ibc z che volume of a liver cell.

b. The image is of cart uk2x9*dy gd;b09 :lmzrxlns )+/bkbdiac 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 ovu6bs tx4gh1eu6r oc h uhahvef81 0/u6)m has specialized to have a large volume.

d. Estimate the mean lengtr.*cu9 .wl8 mwkhl7e eh of a cell with a volume of 1000 µm3 using the trend line on thrl.ul m* eewc 97.8kwhe graph.

e. The horizontal error bars represent laqcrh8 7g3c5 standard deviation. Suggest what the standard deviatioaqlcch 3 785rgn signifies.

f. Simplified models are commonly used to investigatog+cbs7c a.0a) ta) pje 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, distiow5smwcubir 2.gz8 :g5s :cx) nguish between pluripotent, totipoten zux iwgms 5b:2goc:8 w5sc.)rt and multipotent stem cells.

7. Explain the role of stem cells inbgihs )xn8*w 6 a multicellular organism.

(a) Explain why a large surface area to volume rati:6rgcoz65u vwhhw5z 5fi6 4(ai vc3eco can increase cell efficiencyo evc havguc5i w55hirfz:wc46 36(6z.

(b) Describe, using two specific exampl+s+.n1 (fu zyqmhk,x 0swud3j es, how cell adaptation can increase surface ar+dy n mf1xu +uksjs0.3,qzw h(ea to volume ratio in a specialised cell.

(c) Many tissues found in plants are compound tissues, such as phloem tisz f4v0y r 1+aq 7v;(fbn3bbjlssue shown in the image. Phloem tissue transports organic nutrients from their site of production (often, the leaf) to sites of storage orlb0z(3 sbqrybv j a;nf v74f+1 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