MBBS Developmental Biology

Question 1

Axis

Answer 1

Line in relation to which the embryo (or organ) displays a morphological difference.
Examples include rostral-caudal (head-tail, anterior posterior), dorsal-ventral (back-belly),
and left-right

Question 2

Cell lineage

Answer 2

“Family tree” showing the ancestry of a cell in the embryo, tissue, organ

Question 3

Developmental potential

Answer 3

Range of tissues/cell types that a given cell is capable of generating

Question 4

Fate

Answer 4

Cell type/types normally formed by an embryonic cell

Question 5

Stem cells

Answer 5

Undifferentiated cells capable of both self renewable (mitosis) and differentiation

Question 6

Specification

Answer 6

Tendency of a cell/group of cells when cultured in isolation from the rest of the embryo and under neutral conditions, to differentiate in a particular direction

Question 7

Regulation

Answer 7

The ability of a portion of a morphogenetic field to reconstitute the entire field

Question 7

Regional specification (positional information)

Answer 7

Mechanism by which different cells in a morphogenetic field acquire different developmental commitments

Question 8

Regeneration

Answer 8

The ability of a morphogenetic field/tissue to replace missing parts

Question 9

Potency

Answer 9

Developmental potential of a cell or the range of all possible fates that can be produced by the descendants of this cell (either normal fate or alternative- caused by experimental manipulation)

Question 10

Positional information (morphogen)

Answer 10

Provides spatial information across a morphogenetic field to specify different cell fates

Question 11

Polarity

Answer 11

Regional differences in cell commitment along an axis of a morphogenetic field

Question 12

Pattern formation

Answer 12

Synonymous with regional specification but also includes cell movement and sorting processes

Question 13

Organizer

Answer 13

Embryonic region emitting instructive signals responsible for regional specification within a morphogenetic field (signal is usually a morphogen)

Question 14

Morphogenetic field

Answer 14

A portion of an embryo contained within well defined boundaries which can develop independently, without instructive influences from the rest of the embryo. Capable of regulation and gets more and smaller as the field subdivide when development proceeds

Question 15

Morphogen

Answer 15

A molecule that forms a concentration gradient across a morphogenetic field, evoking different cell fates at different concentrations. At least 3 cell types must be formed in response to the gradient

Question 16

Morphogenesis

Answer 16

Formation of a biological structure by changing the relationships of cells and tissues

Question 17

Fate map

Answer 17

A spatial map of the cell fates of different regions of an embryo at a particular stage of development- made by labelling cells at one stage of development and identifying their distribution and commitment at a later stage