In some cases, a nonsense mutation in one gene of a transcription unit was found to prevent the expression of subsequent genes in the unit even though both genes had their own ribosome binding sites, an effect called polarity.

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#Unit 4. Cell Communication and Cell Signaling

Feedback regulation by MAP Kinase

Active MAP kinase phosphorylates Raf on multiple sites, reducing its association with Ras.

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#Unit 5. Developmental Biology

A second glycoprotein secreted during starvation is CMF (conditioned medium factor)

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#Unit 5. Developmental Biology

If the P2 cell is killed at the early 4-cell stage, the ABp cell does not generate its normal complement of cells

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#Unit 3. Fundamental Processes

RNA polymerase can initiate a new RNA chain de novo on a DNA template and thus does not need a primer

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#Id: 5042

#Unit 3. Fundamental Processes

Before replication, the palindromic target GATC site is methylated by dam methylase on the N6 of A of each strand.

Replication generates hemimethylated DNA, in which one strand is methylated and one strand is unmethylated.

Thus, the replication event converts Dam target sites from fully methylated to hemimethylated condition.