1. Which of the following areock8n 1)wck b- roles of 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 describe the differentiated cells in an)nmbya:.z 8s z individual plant such as) mazny:8 bsz. the golden barrel cactusbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties of 0zp /g ;7opu:yjanfb 3stem cells?

  4. What is the cause of stem cells di+ :nf(ejjlds1l bno+r6/ +alrfferentiating along different pathways to produce a variety of differentiat+(1n+alj oj 6l+:dr elfn b/rsed cells?

a. Use the graph to estimate the volume of a liver -od0dcdn +wwl5w da7*cell.

b. The image is of cardiac m sr5 7xl/( ik1bzuzfi:uscle.

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 ;u8:vpro )dlrlized to have a large volume.

d. Estimate the mean lo5iw5dks*kg *ength of a cell with a volume of 1000 µm3 using the trend line on thig5ko5k* s*wd e graph.

e. The horizontal error bars represent standard deviation. Suggest what the t 1l sg* gh-f4y44y 2lfd.l6xgi6spzqstandqlgtyxsgdpz4lf y1l-* 46 gsi4 h2f.6ard deviation signifies.

f. Simplified models are commonly used to investigate scientific kcj.0 eh* ke/v kfi44 0t8grl::shjfsphenomena.
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 betweek rd(3jgcw/spslqf p71m+z5s6ker) x3 l+c 3zn pluripotent, totipotent and 73kgwsl /z ds+c)6kmfp qrzps(l r53 1j 3xec+multipotent stem cells.

7. Explain the role of stem cells in a multicellular organc , c trzaxnv;so81;s8ism.

(a) Explain why a large surface r x- fq.;;vsozarea to volume ratio can increase cell efficiencr-vosf q;.x; zy.

(b) Describe, using two specific examples, how cell adaptation can .qi :/0bq0d pl6mzvtlincrease surface a .0 tp0q6li:lz/qmdbvrea to volume ratio in a specialised cell.

(c) Many tissues found in plazoh7j :iz:npn2.mh,j k2p ; jents are compound tissues, such 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 flowers:ijk pemhjhp.7 jon2n: zz;, 2 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