1. Which of the following are roles of stem cells yyoi7wi68.d lin 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*1nn 30 /xh, npc owwp u6tqts)tj69vi correctly describe the differentiated cells in an individual plant such as the golden barrel cactusbarrel (Echinocactus grusoni/o3 p96) ptnxjt*vqw h,tns0 uni16cwi) shown in the image?

  3. What are essential propertie52ogqgu : i 2pdsehg++s of stem cells?

  4. What is the cause of stem cells differentiating along h)xnx2s *-holdifferent pathways to produce a variety of differ*xosn -2)xlhhentiated cells?

a. Use the graph to estimazfz4u * t 6n9uantj5akax o/)(k45x krte the volume of a liver cell.

b. The image is of c4w4r 4pume qh0xx; na/ardiac 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 specializedtb0yp:n zk8t-srw o8zipi x)rj ;v(,( to have a large volume.

d. Estimate the mean length of a cell with a volume of 1000 µm3 using ttib2* y:*x)d4du,*u3xmvit d whx8g ihe trend line on u*x 2 4xyd,i* vu8m:t 3bgtd h*w)ixdithe graph.

e. The horizontal error bars represent standard decq 1erl;pos( +8yx4:ddpcd 3mviation. Suggest what the standard devi 4op:+dyl8sc m;1pdqx r( 3ecdation signifies.

f. Simplified models are commonly used to investigazbs6oic*n0wb- : n ap 8mywuy.ej6 ,t(te 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, distu 9/nl ;f5e:qw;m,s9yikcavcinguish between pluripotent, totipotent and n9;v5c kyl / :9mue,wacq;si fmultipotent stem cells.

7. Explain the role of stem cells in a multx 5 qmux*s:,z6sxlryq*i(h+iicellular organism.

(a) Explain why a large surface area to volume ratio z. 9jyp,4pm4fqnu26kh+ 8 8xc os cuxkcan increase cell efficiency.y. hx9f4sujkcz,xnc26pom + 8qp4uk8

(b) Describe, using two specific examples, how cell adaptat z 4xwa(4zuz/kion can increase surface aw4z/4 z(kzxa urea to volume ratio in a specialised cell.

(c) Many tissues founds:6at goz 7qk.le5es* in plants 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 e. g*5o7sqs e:tzal 6kof 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