1. Which of the following are roles of stem cells po yx9nm 43nb2g*b9ug 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 3 /r/he/+ btz1eo.jap xs-ibxbr/ 0sy the differentiated cells in an individual plant such as the golden barrel cactusbarrel (Echinocactus grusonii)b r-ej xbx0p/btr/o1 se y+i/zha/s 3. shown in the image?

  3. What are essential yk dz8: (mlsg8properties of stem cells?

  4. What is the cause of stem cells differe rj+mi9m0v x4vntiating along different pathways to produce a variety of diffr0i+j9v x4 mmverentiated cells?

a. Use the graph to estimate the volume of aqg2w(pfb5; ta liver cell.

b. The image is of cardi833e 0vagydceejjsgz-;h,mz- 4 )z ff ac 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 specialized to have a large volumey n9rs5 gie rle93z35kh ew lk;7xr/9g.

d. Estimate the mean length of a cell wi8akrcau9 8w 0zth a volume of 1000 µm3 using the trend line on the z88wr ck9a 0uagraph.

e. The horizontal error bars represent standard devij( fc.v;v t yht6nq-)mation. Suggest what the standar.q-thvfy6 ;jncv m) (td deviation signifies.

f. Simplified models are commonly used to investigate sn-h p 6.ujdo.mcientific 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 betwumk, oi 59ftp62,r avmeen pluripotent, totipotent and multik utfpr omv,m296i5, apotent stem cells.

7. Explain the role of stem cells in a multicellular organism. -k1 cpw1,ch51b-n mu +ighqbm

(a) Explain why a large surface area to volume ratio can in+fvqkys+ 8;mrn6l/ t xb:(as hcrease cell efficiency. ry sq+ak;(thv/s bfx8mn:+l6

(b) Describe, using two spq6kvfq*n5rfs1 p6ax8 ecific examples, how cell adaptation can increase surface area to volume ratio in a nrx5qka p6f8q f1vs6*specialised cell.

(c) Many tissues found i/s5p ni/e mlu(8svf/b 1s1xben 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 s b /(l 1ne1umvxs/i85p sebsf/ites 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