The results of Meiosis I are two diploid cells with genetic differences on the chromosome. These differences are a result of crossing-over. Crossing-over is a process that happens after both homologous chromosomes in a pair join up to form a structure called a tetrad. Tetrads form through a process called synapsis.
A tide is the periodic rising and falling of Earth's ocean surface caused mainly by the gravitational pull of the Moon acting on the oceans. Tides cause changes in the depth of marine and estuarine (river mouth) waters. Tides also make oscillating currents known as tidal streams (~'rip tides'). This means that being able to predict the tide is important for coastal navigation.
The lowest high tides (or neap tides) occur when the Moon and Sun are at right angles to each other, so that their gravitational pull on Earth's waters originates from two different directions and is mitigated. Tides vary greatly by region and are influenced by sea-floor topography, storms, and water currents.