Magnification & stem cells

Question 1

What happens to the area you see as magnification increases?

Answer 1

The area of the field of view decreases and the resolution of the image isn’t as clear

Question 2

What areas of the plant have the ability to grow?

Answer 2

Meristems

Question 3

Where are meristems found?

Answer 3

At the apices (just behind the tip of shoots and roots)

Question 4

What are stem cells?

Answer 4

Unspecialised cells that have the ability to divide and become any type of cell required by the body

Question 5

Name some ethical concerns behind stem cells

Answer 5

• theoretically humans could be cloned

- harvesting of the cells may result in the abortion of the embryo

Question 6

Name 3 limitations of adult bone marrow stem cells:

Answer 6

• not all cell types can be produced, only specific types of blood cell
• cells have a limited life span
• cells can be hard to grow

Question 7

Define diffusion

Answer 7

Diffusion is the random molecular movement of molecules from a region of high concentration to a region of lower concentration along a concentration gradient.

Question 8

Give an example of diffusion

Answer 8

Dye crystals in a beaker of water

Question 9

Give 3 examples of where diffusion is important in biology

Answer 9

• gas exchange in the lungs
• gas exchange in leaves during photosynthesis
• absorption of digested food molecules in the gut