Adenine and guanine are also subject to spontaneous deamination. Deamination converts adenine to hypoxanthine, which hydrogen-bonds to cytosine rather than to thymine; guanine is converted to xanthine,

which continues to pair with cytosine, although with only two hydrogen bonds.

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#Id: 2274

#Unit 3. Fundamental Processes

E. coli encodes several other s subunits that can replace σ 70 under certain circumstances.

a.σ 32 

b.σ 54

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#Id: 8488

#Unit 1. Molecules and their Interaction Relevant to Biology

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#Id: 8417

#Unit 10. Ecological Principles

Many large mammals, including humans and K selected individuals – Type I curve 

Many birds, small mammals, reptiles and some annual plants – Type II curve 

Many fish and marine invertebrates, r selected individuals - Type III curve

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#Id: 2647

#Unit 13. Methods in Biology

In G-less cassette, transcription will stop at the end of the cassette where the first G is required, yielding an aborted transcript of predictable size (based on the size of the G-less cassette, which is usually a few hundred base pairs long).

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#Id: 407

#Unit 2. Cellular Organization

In Drosophila, the centromeric chromatin appears to consist of “hemisomes” containing one copy each of CenH3, H4, H2A, and H2B.