1. Which of the following are roles of stem cells1pod6;w 2eum d 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 deyrvq(ecwo(bn3d(kqn: cy / 69scribe the differentiated cells in an individual plant such as the gol3n(dkvoq:ne q9/ cw(r(yy b c6den barrel cactusbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties ov1qxk .5- p peoog8v:tf stem cells?

  4. What is the cause of sf(k 9ur5bttwxwb, -b;tem cells differentiating along different pathways to produce a varietw ,xtf;5 wb rkbu(-b9ty of differentiated cells?

a. Use the graph to estimate the volume of a 9c 0i2m*xc6tooymey sx63,lm liver cell.

b. The image is of cardiac musccv) ymb2 k9, bxacb01ile.

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 whyb 0f8f3dvd8bng cn:c0 a human ovum has specialized to have a large volume.

d. Estimate the mean length of a cell with a volume of 1000 µm3 using the tre)xoah4 p2 1 +ozpp3gkvnd line on 1+ go4p op2v3z)k xpahthe graph.

e. The horizontal error bars represent standard deviation. Suggest what the sto0ej+ au.j+v* tbj7fhandard deviatio+a0 hf v+o7. j*jetbjun signifies.

f. Simplified models are commonly u i2wqp:p94m2 6kx qgcomotf2.sed 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, totipotenci5 : 6mvf3r:)fzqeytt and multipotent stem celqvy6i )5tefr: fm3zc :ls.

7. Explain the role of stem dy/:h9uqa1 nxs 8wurammg ,;p3 xjgn)2 :zlv8 cells in a multicellular organism.

(a) Explain why a large surface area to volume ratio can increase cell +wrll62qqcjju,zj t7p(youonl(,6- efficiency.6tcz(uy6joq 7, lw p( -nl+2qljjur, o

(b) Describe, using ig3k3ibt sc( 8two specific examples, how cell adaptation can increase surface ar(3c sikbg83 tiea to volume ratio in a specialised cell.

(c) Many tissues found in plants are compound tisd* t2rf+m-43o s8 fmj*hjky ;:kpbmu ysues, such as phloem tissue shown in the image. Phloem tissue transports organic nutrients from their site of production (often, the kfdhu3skm2jmyj -fy pm4*r+o;b*8 :tleaf) 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