1. Which of the following are roles of stem c tpuivyvbby96cs: r6s48y .0cells 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 dmu.4xx*kw 9geescribe the differentiated cells in an individual plant such as the golden9w.g mexx* u4k barrel cactusbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties of steyq/qsdxkfuo( f k9r56kh 94( rm cells?

  4. What is the cause of stem cells differentiating along different nfdm i4pcxf kx12by 2(4osy6;pathways to produce a variety of differentiated46m yi2o4 1(f2cpxks;nbxdfy cells?

a. Use the graph to estimak78u4 tvpmyf8so9.j wte the volume of a liver cell.

b. The image is of caran: /+auli(xodiac 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 oaopcir(03 +w evum has specialized to have a large volume.

d. Estimate the mean length of a9 + f m 4wcn*qb95hz0llv.jgzo cell with a volume of 1000 µm3 using the trend lin m +fq40z.9gnljcovl5* 9zhwbe on the graph.

e. The horizontal error bars represent standard deviation. Sugg f.6ypsh8krx(est what the standyhfsr.x6 kp( 8ard deviation signifies.

f. Simplified models are commonly used to investigate scientifutpm ;p 2h(ie9sll q01 a0jm5kic 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, tyo ick *ht8.i+otipotent and m8 ky+c o.hiit*ultipotent stem cells.

7. Explain the role of stem cells in a porr /+a g wuc:v7 7c7q6pz2kmmulticellular organism.

(a) Explain why a large surface area to volume ratio can increase cell efficienclocmq ka6)c dk :18id0ydaco1c kq0kl6:mdi 8 ).

(b) Describe, using two specific examples, how cell adaptation can incrbchf.5- gbq vp(1 oog/ease surface area to v5 o(. gfb1obqch/ -gpvolume ratio in a specialised cell.

(c) Many tissues found in plants are compound tissuesr w1m)qeh)/c 8dgn,ho, such as phloem tissue shown in the image. Phloem tissue transports 1nw) eqgoc,hr/8hd m)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