1. Which of the following are roles of stem cells in livin,tdlm8i(o.h)e s past* z;c8 zg 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 followi-t1t66z h,yd9ynejsu 3s ak 1ang correctly describe the differentiated cells in an individualt3 k,u-9 6 zje61hat dysy1sna plant such as the golden barrel cactusbarrel (Echinocactus grusonii) shown in the image?

  3. What are essential properties of s8vy1., ru(uv0guvtlo 9ep0aftem cells?

  4. What is the cause of stem cells differentiating along different paivp.c e/v/h8b8ob +yfthways to produ i hv+./88fyvc/bbeopce a variety of differentiated cells?

a. Use the graph to estimate the volumgh5c :/5du nvgow s4u-e of a liver cell.

b. The image is of cardiac muscle. jje 6yjssh,r11a-l t;

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 hy oqs.h. rg,z4as specialized to have a large volume.

d. Estimate the mean length of a cell with a v7e0zur 3fbmp 6olume of 1000 µm3 using the trend lin 6e3rfzu0pbm7 e on the graph.

e. The horizontal error bars represent standna dajab kl, p1)c- s6za87c+fard deviation. Suggest what the standard deviapcna saf1lj6 +8)dk c,aab7-ztion signifies.

f. Simplified models are commonly used to iz3: e xrcr0hp5nvestigate 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 plrjbclr*l.r0 2 uripotent, totipotent and multipotentrlcbrj*lr 02. stem cells.

7. Explain the role of stem ce;utk(, +8mjrbng :zgmlls in a multicellular organism.

(a) Explain why a large surface areao-)5awy6w m7dw11v q monmwi9 to volume ratio can increase cell efficiency.o)nwq1wm wv y7-o5d69wam i m1

(b) Describe, using two specific examples, how cell adaptationjdfs6j r:*+ke 1 0xvsm can increase surface area to volume ratio in a specisms vfj*+61 j: rde0kxalised cell.

(c) Many tissues found in plants are compound tissues, such as phloem tissu3/rgtuf zl--/ei l4tz5ce -i ke shown in the image. Phloem tissue transports organic nutrients from their site of production (often, the leaf) to sites iz/u/-4 -fzrlk gi5tc 3etle-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