1. Which of the following are roles o5 cuiz uf q4sxpv)51l6f stem cells in 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 describ7.+s7plk. pi ;k5s iwh:grdnm e the differentiated cells in an individual plant such as the golden barrel cactusbarrel (Echinocacti :insgkpd ;.5h7p.wmls 7kr+ us grusonii) shown in the image?

  3. What are essential properties b4/j0qumwt aj4ms:2w of stem cells?

  4. What is the cause :t6.)vm k9wgxi0amh q of stem cells differentiating along different pathways to produce a variety of differentia)atm:9x0 vwmh gq6.kited cells?

a. Use the graph to estimate the volume 8)1rkj yg4j0rrei* +;vyv/dx6h qmyqof a liver cell.

b. The image is of ca6z,z kpeg:ais 0/snu1rdiac 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 spe qcu1 11b;r2hik)jmhrcialized to have a large volume.

d. Estimate the mean length of a cell with a volume of 100a/7mp 8x3uey oni0 (ii0 µm3 using the trend line on the graphiy/ oie7i3 8um(pan0x .

e. The horizontal error bars represent standsnr+z;h * 9ps*ne7zliite3mglpf.6 - ard deviation. Suggest what the standard deviationghl3n6. z+ifelps z ip;9e*t 7mr*n -s signifies.

f. Simplified models are commonly used to investigate scientific phenome e ck 96me2sgrfk9tw7vb b9;(ena.
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 pluripotenaib-co(n lqt5 ui dmq9 3v8;0kt, totipotent and mio bqa(k8dnml iv;-0 ct593qu ultipotent stem cells.

7. Explain the role of stem cells in a multicellular organ7 fj(u55tkflbism.

(a) Explain why a large surface area to volume ratio can increase cellxp bqhx7fdj7(a2,,gj7r bk g0gixj x*(lq3b 1 efficiencb(1 7 fglxkqjgxipx3(qjah7, x bd7b*r, j g20y.

(b) Describe, using two specific examples, how ced2i1/2g i. e 8xrpogx:w3qm 0qihi p2 +dlrkk2ll adaptation can increase surface area to volume ratio in a specia3qkmqxh okwp i2i/0d.2i e2 8 2: gxrrldig+p1lised cell.

(c) Many tissues founr8g0-r (a.0,ov0p zz nbeastz4pir : vd in plants are compound tissues, such as phloem tissue shown ingro4:0vz(0szpe nztabv p80a .- ri,r the image. Phloem tissue transports organic 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