Book

Question 1

define regeneration

Answer 1

process of molding tissues into an exact replica of missing parts

Question 2

epimorphosis

Answer 2

lost parts are built anew from a population of undifferentiated cells

Question 3

morphallaxis

Answer 3

differentiated cells are remodeled into new parts

Question 4

pattern formation

Answer 4

the process of creating specific patterns and shapes out of tissues

Question 5

positional information

Answer 5

the information necessary to create these patterns and shapes

Question 6

diffusion gradient model

Answer 6

positional information is established by a gradient of a chemical substance (morphogen)

Question 7

polar coordinate model

Answer 7

cells recognise their position in the whole because of positional information that each cell receives designating where the cell is in relation to the rest of the organism

Question 8

What did Mead & Krump 1986 establish about planarians?

Answer 8

the ratio of length to width in a slice taken from a planarian that determines whether it will regenerate normally, and not absolute width of slice

Question 9

what sort of regeneration do planarians undergo?

Answer 9

epimorphosis but some research indicates that morphallaxis may also play a part

Question 10

define morphogen

Answer 10

a diffusable molecule, secreted at a distance from its target cells, that specifies the fate of the target cells. It may specify more than one cell type through a concentration gradient of the morphogen, in which case different concentration determines different cell fates.