Development Of Multicellular Org I Flashcards Preview

Molecular Biology Exam 3 > Development Of Multicellular Org I > Flashcards

Flashcards in Development Of Multicellular Org I Deck (33):
1

T/F: Genes expressed by a cell depend on the PAST Environment.

False


Both PAST and PRESENT

2

Gastrula

- Mature form of Blastula

- Has 3 major layers

3

Gradients in morphogenesis are formed by what?

1. Localized production of an INDUCER that diffuses AWAY from its source


2. Localized production on an INHIBITOR that diffuses AWAY from its source
- Block the action of a uniformly distributed inducer

4

What are the most important Environmental cues for inductive signaling?

Signals from Neighboring cells

5

What do Cells do BEFORE acquiring a particular fate?

- Cells express genes that are markers of their Location

- Regionally determined

6

Which cell wins in Delta Notch Signaling?

The cell with the ACTIVE Delta

- Inhibits its neighbors from doing likewise

7

Response to whether genes are turned “on” or “off” are in response to what?

Spatial and Temporal expression of different sets of genes

8

How do Zebras get their stripes or Leopards get their spots?

Pattern generation by Reaction Diffusion

- Long range inhibition

9

Characteristics of Committed Cells

- Cell that have some attributes of a particular cell type

- But CAN change with Environment

10

Characteristics of Completely Undetermined cells

Cells that Rapidly change due to alterations in environment

11

Characteristics of Inductive Signaling

Induction of DIFFERENT developmental program in select cells of homogenous group

- Leading to altered character

12

Conserved mechanism for development

1. The cleaved cells do NOT feed
- depend on the food STORED in egg by the mother

2. Genome is Inactive

3. Once activated cells form blastula
(Hollow ball of cells)

13

Instructions for producing a Multicellular Animal is contained where?

NON-Coding Regulatory DNA

- Associated with each gene

14

Diversity is a pattern due to what # factors?

1. Gene Duplication

2. Presence of other signals
- Combinations create variety

3. Previous experiences of the cell

15

Gene Duplication

Higher organisms have several homologous of the SAME gene

16

Endoderm is the precursor to what?

- Gut

- Lung

- Liver

17

4 stages of a. Developing Embryo

1. Cell Proliferation

2. Specialization

3. Interaction

4. Cell Movement

18

T/F: HOMOLOGOUS proteins are functionally Interchangeable

True

Fly protein can be put into a Mouse to rescue development of Cerebellum

19

What controls development?

Gene Expression

20

Asymmetric Division

Significant sets of Molecules distributed unequally between daughter cells

21

Asymmetry and Positive Feedback timeline

- System starts symmetrical

- Environment poses a Weak Asymmetry

- Poz feedback amplifies it

- IRREVERSIBLE

22

How many genes does a human share with a fruit fly?

50%

23

When are developmental decisions made for differentiation?

Long before they show any outward signs of differentiation

24

What is Positional Value?

Position Specific Character of a Cell

25

Mesoderm is the precursor to what?

- Muscles

- Connective tissue

26

What proteins are most important for development?

Gene Regulatory Proteins

27

What sequence makes one organism different from the other to provide uniqueness?

NON-Coding Sequences

28

Characteristics of Determined Cells

- Cella that are fated into SPECIALIZED cell type

- Despite changes in environment

29

Common Signaling Pathways

1. Receptor Tyrosine Kinase (RTK)

2. Transforming Growth Factor (TGFβ)

3. Hedgehog

4. Notch

5. Wnt

Roy Touches Hung Narrow Wieners

30

What is a morphogen?

- A long range inductive signal

- Imposes a pattern on a field of cells

- Exert graded effects by forming gradients of different [ ]

31

What is the ultimate result of Inductive events?

Change in DNA transcription

32

Short Range vs Long Range signaling

Short:
- Cell to cell contact


Long:
- Substances that can diffuse through the EC medium

33

Ectoderm is the precursor to what?

- Nervous System

- Epidermis

- Gives rise to the ENDODERM