Developmental Bio

Question 1

Define pre formation
Epigenesis

Which did Aristotle prefer

Answer 1

1) organs+tissues preformed and correctly positioned and fertilised egg - simply enlarge

2) organs and tissue formed gradually , complexity of embryo increasing - preferred by Aristotle

Question 2

What did Anthony’s van Leeuwenhoek discover, and what did this make popular in Late 17th century?

Whats the homunculus theory ?
What did it not explain?

Question 3

Axis - give 3 examples

Answer 3

Line across embryo w morphological difference , e.g. rostal-caudial ( head- tail / anterior/ posterior), dorsal- ventral ( back- belly) , left-right.

Question 4

Cell lineage
Also similar to what

Answer 4

Similar to fate mapping or family tree - shows ancestry of cell in embryo /tissue/organ . Mainly used in experiments where cell followed and observed to find final fate. Cell marked or observed.

Question 5

Commitment - 2 meanings depending On scientist.
Also similar to what

Answer 5

Determination - irreversible decision to differentiate in specific direction.
Some say cell committed to partical fate - maybe reversible.

Question 6

Competence , definition and 3 things it depends on.

Answer 6

Ability of cell to respond to inducing signal.
Depends on - expression of appropriate receptor for inducing factor - intact signal transduction cascade - epidemic state of target genes (may respond or not )

Question 7

Cytoplasmic determinant , what is it usually ?

Answer 7

Substance localised to part of egg/blastomere - assymtrically distributed during cell division. Guarantees specific commitment for cell.
Usually Transcription factor.

Question 8

Determination

Answer 8

Irreversible commitment to specific cell fate- made by stem cell. Same developmental potential as cell fate.

Question 9

Differentiation

Answer 9

Cell acquired final characteristics. Manifestation of cell fate. Cell has clearly defined morphology and histological type.

Question 10

Embryonic induction

Answer 10

Signalling interaction between inducing and responding cells , where responding cells undergo xhange of fate. Inducing factor used.

Question 11

Fate

Answer 11

Developmental potential.

Question 12

Fate map

Question 13

Morphogenesis give 2 examples

Answer 13

Formation of bio structure by changing cell relationships.
Gastrulation and neurulation

Question 14

Morphogen

Answer 14

Forms conc gradient across morphogenic field - evokes different cells fates at diff conc.s must result in atleast 3 cell types - otherwise an inducing factor.

Question 15

Morphogenetic field

Answer 15

Can develop independently w out instructive influences. Capable of regulation - portion can reconstitute whole field. As developmental proceeds - fields subdivided- become smaller and more numerous.

Question 16

Organiser

Answer 16

Embryonic region emitting instructive signals for regional specification within morphogenic Field - usually morphogen.

Question 17

Pattern formation

Answer 17

Includes regional specification, cell movements and sorting processes.

Question 18

Polarity

Answer 18

Regional differences in cell cell commitment along axis of morphogenitic field.

Question 19

Positional information

Answer 19

Provides spacial info across MF

Question 20

Potency

Question 21

Regeneration

Answer 21

Ability of MF or tissue to replace missing parts

Question 22

Regional specification vs specification

Question 23

Regulation

Question 24

Stem cells

Question 25

What are the 7 main stages of development

Question 26

What are the 3 germ layers Total of 11 tissue types- which germ layer does each develop from

Question 27

What happens to flexibility of differentiation as complexity increases- why ? What is this process called

Answer 27

Complexity increases - variety of things that cell can differentiate into or flexibility decreases Lineage restriction

Question 28

Stages of potency of stem cells and what they mean and examples (5)

Question 29

Identify all vertebrate body plan sections, position, function, and remember they are not differentiated yet just stem cells. What about amniotic membrane and umbilical chord?

Question 30

Stem cells divide into what 2 types of cell? Why is this essential? If it’s just stem cells than what happens? If it’s just differentiated cells then what happens?

Question 31

What’s cell commitment ? Why is it significant ? What role does lineage restriction play ? Give example of flow chart for epiblast into skeletal muscle - w all options along the way

Question 32

What are the 3 stages of commitment? Explain each .Which stages are reversible and what’s not?

Question 33

3 mechanisms of cell commitment ?

Question 34

Who discovered determinants and when? Localised determinants are what type of development ? How do they work ? How did the discovery of yellow cytoplasm contribute to determinants ?

Question 35

What and by who and when was the first experiment of embryology ? Method and results, conclusions and suggested mechanisms ?

Question 36

What’s regulative development ? What experiment was done related to it? By who and when? Why did it disproved determinants theory ?

Question 37

What experiment did Spemann do in 1903 and what did it prove? What did roux do wrong in his experiment ?

Question 38

What was hilde mangold’s experiment on embryonic induction? Method, results and conclusion ?

Question 39

Label all parts of a diagram showing neural induction.

Question 40

Define neural induction

Question 41

How does a cell fate form a neurone? Which of the 3 layers is it first restricted to? Next step? One after?(which part of NS), then finally cell splits into neuron and what ? When do cytoplasmic determinants vs induction play a role throughout the process?

Question 42

What are the 4 developmental signals?