Most likely an altimeter,
microscopes can be too heavy to carry outside,
x-ray diffraction is used to determine the molecular structure of a crystal so that is not likely to be helpful,
but an altimeter determines the altitude of an object on a fixed level, so that can be useful during a field investigation
hydrometers-measure gravity of liquids, probably not useful for a field investigation
<h2><em>the DNA that is packaged into chromosomes must be fully copied. Previous to replication, a germ cell contains two copies of each chromosome, a maternal copy, and a paternal copy. ... DNA replication occurs in the same fashion as it does during mitosis.</em></h2>
In eukaryotic cells, or cells with a nucleus, the stages of the cell cycle are divided into two major phases: interphase and the mitotic (M) phase.