Stem cells are sometimes referred to as “undifferentiated” due to this maintenance of proliferative properties.

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#Id: 10307

#Unit 4. Cell Communication and Cell Signaling

T-Cell Differentiation

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#Id: 8119

#Unit 1. Molecules and their Interaction Relevant to Biology

The triterpenes are C30 terpenes and include squalene and lanosterol, two of the precursors of cholesterol

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#Id: 2048

#Unit 8. Inheritance Biology

X-Linked Recessive Trait

a. Usually more males than females are affected.

b. Affected sons are usually born to unaffected mothers; thus, the trait skips generations.

c. Approximately half of a carrier (heterozygous) mother’s sons are affected.

d. Never passed from father to son.

e. All daughters of affected fathers are carriers.

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#Id: 2066

#Unit 8. Inheritance Biology

Heritability- Phenotypic variation that is due to genetic differences

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#Id: 6885

#Unit 3. Fundamental Processes

DNA methylation and macroH2A contribute to the stable repression of the inactive X chromosome  A. Wutz and J. Gribnau, Curr. Opin. Genet. Dev. 17 (2007): 387–393. inactive specific transcript), which is stably expressed only on the inactive X chromosome.