1. Which of the following are roles of stem cells in living orga07cdru:6 wry pnisms?
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 corr;r*h dl)+qgtwflnw0- 6t g.wa ectly describe the differentiated cells in an individual plant such as the golden barrel cactusbarwa; fw6. nhd qtlg-tlwr*)0g+rel (Echinocactus grusonii) shown in the image?

  3. What are essential proper+vi*s-+f-u.pe k fjfzk.c qw7 ties of stem cells?

  4. What is the cause of stem cells differentiox44y7eaw sfmp j+p-3:uus4eating along different pathways to produce a variety of differentiated cells sx47a ew+fjs:m4epu-34yopu?

a. Use the graph to estimate the volume of a ss3qr rz/-( 9n8 nexfqjv.dg 7liver cell.

b. The image is of cardiac b 1zf. gyz.d,omuscle.

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 wbze;d 5t a 6jjjv3n/5xhy a human ovum has specialized to have a large volume.

d. Estimate the mean length of a cell with a volume opo l,t;f6t ap:f 1000 µm3 using the trend line on the gra,ft ta6lo;pp :ph.

e. The horizontal error bars represent standard devia oz wc8)qdo.8w5ev0 cxr4om1gtion. Suggest what the standard deviati deoxv0qwg48c15o mr w cz8o).on signifies.

f. Simplified models are commoocqrqq tt7bd w18nw,, 3mz18znly used 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 plubifqc/:y h :cy1b+am1*3jvl yripotent, totipotent and multipojcy/q1yvm 3yi:*fhb+l:a1 b ctent stem cells.

7. Explain the role of+1 mzk bpcfo8 olp85edkx5t;: stem cells in a multicellular organism.

(a) Explain why a large surface area to volume ratio can increase cey: p:fuo:lofo 9n(./s0wn riull efficiency. .p u9s:(:/:r y 0fofnliowuno

(b) Describe, using two specificdho.iidajkv .tb;31 mi,8enr weu*. 2 examples, how cell adaptation can increase surface area to volume ratio in a speciaioi.rkd 1. e;2ne d8ahujt*bwim ,.v3lised cell.

(c) Many tissues found in plants are compound tissues, 3+/fkz ,qhlgl such as phloem tissue shown in the ll+3fzqh, g /kimage. 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