Hemlock (Cicuta sp.) produces cicutoxin, a polyacetylene that prolongs the repolarization of neuronal action potentials.

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#Id: 89

#Unit 5. Developmental Biology

There are three different modes of cell specification: 

1. Autonomous

2. Conditional

3. Syncytial

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#Id: 90

#Unit 5. Developmental Biology

Autonomous Specification

Cell “knows” very early what it is to become without interacting with other cells

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#Id: 91

#Unit 5. Developmental Biology

Autonomously specified cells capable of differentiating autonomously (i.e., by itself) when placed in an environment that is neutral with respect to the developmental pathway.

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#Id: 92

#Unit 5. Developmental Biology

In Autonomous Specification

Prospective potency is equal to prospective fate.

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#Unit 5. Developmental Biology

Autonomous Specification

Produces "mosaic" ("determinative") development 

Cells cannot change fate if a blastomere is lost

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#Id: 94

#Unit 5. Developmental Biology

In Autonomous Specification, 

Cytoplasmic determinants are apportioned to different blastomeres of the early embryo.