The meiotic telomere cluster is visualized by telomere fluorescent in situ hybridization (FISH). Microscopic image of a maize nucleus fixed at meiotic prophase (zygotene stage), subjected to telomere (green) and centromere (white) FISH, and counterstained for total DNA with DAPI (red).

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#Id: 7075

#Unit 3. Fundamental Processes

isoleucyl-tRNA synthetase has a nearby editing pocket (a deep cleft in the enzyme) that allows it to proofread the product of the adenylylation reaction. AMP-valine (as well as adenylylates of other small amino acids, such as alanine) can fit into this editing pocket, where it is hydrolyzed and released as free valine and AMP. In contrast, AMP-isoleucine is too large to enter the editing pocket and is therefore not subject to hydrolysis. As a consequence, isoleucyl-tRNA synthetase discriminates against valine twice: in the initial binding and adenylylation of the amino acid (discriminating by a factor of 100), and then in the editing of the adenylylated amino acid (again discriminating by a factor of 100), for an

overall selectivity of 10,000-fold (i.e., an error rate of 0.01%).

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#Id: 5476

#Unit 7. System Physiology – Animal

The synapse between a motoneuron and a muscle fiber is called the neuromuscular junction

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#Id: 4750

#Unit 5. Developmental Biology

During first cleavage, the metaphase plate is closer to the posterior, & fertilized egg is divided into two cells:

one having the anterior PARs (PAR-6 and PAR-3)

one having the posterior PARs (PAR-2 and PAR-1)

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#Id: 1909

#Unit 4. Cell Communication and Cell Signaling

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#Id: 2633

#Unit 13. Methods in Biology

The probe must span the sequence where the transcript starts or ends. After hybridizing the probe to the transcript, one applies S1 nuclease, which degrades only single-stranded DNA and RNA.