1. Which of the following are roles of stem cells ic7k)puz6t8 lt n 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 d kpw5vl y,c.8correctly describe the differentiated cells in an individual plant such as the golden barrel cactusbarrel (Echinocactus grusonii) shown inkycp ,v .5w8ld the image?

  3. What are essential propjo q(d t(w ln*s3ajstji 67 ss0/2yx 0hqk.tc;erties of stem cells?

  4. What is the cause of stem cells differenvl 8e -oa7;nbntiating along different pathways to produce a variety of differentlnvoa- eb8;n7iated cells?

a. Use the graph to estimate the voluma ,elp f43enb pv5(sr3e of a liver cell.

b. The image is of cardiac muscle. qn, z,hj4)o)hm)lp h t

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 hu .yxae-(jl erlvw 1brec672-cman ovum has specialized to have a large volume.

d. Estimate the mean length of a cell with a volume of 1000 µm3 using t5u6r/71u3 j a c pl1qj(zheye z*snniq4thx6,he trend line onjn 1 *n3qxezuup1q/ae(5 7jli,t6ysh hrz4c6 the graph.

e. The horizontal error bars represent standard deviation. +9 kgp+bedzu.1e* eti Suggest what the standa19 .te*z eudbeik+p +grd deviation signifies.

f. Simplified models are commonly used to invested(0)u b l3 rwl3dltj*/7 wmefigate 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 bbtl7t7)fs8lp+ cc- kxetween pluripotent, totipotent and multipotent stem c8)cstkbft7- 7 + lpxlcells.

7. Explain the role of stem cells in zs; 2ejxbkg/q*ky tg1t52cp(a multicellular organism.

(a) Explain why a large surface areae5,:v9xd2ow c,omynn.:nd rl to volume ratio can increase cell efficiency.x 9wydmd:rn ,:. 5,lenonv2oc

(b) Describe, using two specific examples, how cell adaptation can inces rq90 4h1ocerease surface area to volume ra1 rcoeh0 se4q9tio in a specialised cell.

(c) Many tissues found in plants are compound tissues, such as 8uh- jaa -)m)pte8ji fmo+6 bophloem tissue shown in the image. Phloem tissue transports organic nutrients from their site of productio6mj i)+8om -hja-ep)8fu b aton (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