1. Which of the following are role/o55w+f w lwd x0ijpeh(odh73s 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 th2ant+ r/)b ewve differentiated cells in an individual plant such as the golden barrel cactusbarrel (Echinocactus grusonii) s)2+nwv raet/b hown in the image?

  3. What are essential properties og/wj4 alpx : 0od,th5hf stem cells?

  4. What is the cause of sjq: k:3bdqd-3zd8wuptem cells differentiating along different pathways to prodp:q: udjdkwq b33z8d-uce a variety of differentiated cells?

a. Use the graph to estimate the volume of a liver cw05;cvwtn*/o yq y 4hxzc-u3iell.

b. The image is of cardbei o:w6;;ta x(gjch7 iac 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 sp+tzmbprr ;o;:.lbhm 8ecialized to have a large volume.

d. Estimate the mean lengsx g usx+/h*n,sp+y;l th of a cell with a volume of 1000 µm3 using the trend line on +ss /+ush y*pl,gxx;n the graph.

e. The horizontal error bars represent standard devibaq pg jrk)5+u-hz s-3ation. Suggest what the standard devu3-)+gzqjpbrka hs-5 iation signifies.

f. Simplified models are commonly used to invem si:4x5. : x7gmn cr/ztsqav-stigate 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, dis *s3cwmxag+1tmu 8dw 1tinguish between pluripotent, totipotent acu 1*tmxm ww3s+1dg8 and multipotent stem cells.

7. Explain the role of stem cells in a mu)iba3m nvhekrqn9 3 (,lticellular organism.

(a) Explain why a large surface area to volume ratio can increase cell (mcu zsd xn*,h9ne(p8efficiencnh,*pxs(8dn( c mezu9y.

(b) Describe, using two specific examples, how cell adan psf,m7 4meri1**pghptation can increase surfa 4mfi * ,1g7*epnmphsrce area to volume ratio in a specialised cell.

(c) Many tissues found in plants ar(kee gc5.tg lbypu+p-an 6j/u6: ouo8e compound tissues, such as phloem tissue sho:.o-g+gu8et6c apu6nuky lj5oe bp (/wn in 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