In the classic Meselson and Stahl experiment, Coli are first grown in 15N-enriched media (0th generation) and subsequently switched to 14N media. A DNA sample isolated during the first generation of E. Coli grown in 14N media is subjected to a centrifugation step in a dense CsCl gradient. Assuming that replication occurs in a semiconservative fashion, the DNA sample will .

Options are not provided inthe question. Th ecomplete question is as following:

In the classic Meselson and Stahl experiment, Coli are first grown in 15N-enriched media (0th generation) and subsequently switched to 14N media. A DNA sample isolated during the first generation of E. Coli grown in 14N media is subjected to a centrifugation step in a dense CsCl gradient. Assuming that replication occurs in a semiconservative fashion, the DNA sample will .

1) run as two bands (of equal intensity), one at the same position as a uniformly 15N-labeled DNA, and one at the same position as a uniformly 14N-labeled DNA.

2) run as one band, at the same position as a uniformly 15N-labeled DNA.

3) run as one band, at the same position as a uniformly 14N-labeled DNA. run as one band, at a position expected for a DNA containing a 14N:15N ratio equal to 7.

4) run as one band, at a position expected for a DNA containing a 14N:15N ratio equal to 1.

1)

Explanation:

In 1957, Meselson and Stahl gave an experimental evidence for semi-conservative replication  of DNA, means that each DNA strand act as template for synthesis of new DNA.

For the experiment, they use  E. coli grown in heavy isotope of 15N nitrogen and switch to 14N nitrogen undergoing one, two, or three generations and the DNA samples are collected. The DNA samples are then mix with cesium chloride and separated as light and heavy DNA.

As the replication occurs in a semiconservative fashion, the double DNA sample will run as two bands with intermediate density, having mixtures of 15N and 14N DNA, either of which would have appeared as DNA.

Hence, the correct option is (1).

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1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.