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.
Seven days after a spring tide, the sun and moon are at right angles to each other. When this happens, the bulge of the ocean caused by the sun partially cancels out the bulge of the ocean caused by the moon. This produces moderate tides known as neap tides, meaning that high tides are a little lower and low tides are a little higher than average.