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.
What Causes the Tides? By Rick Groleau; Posted 11.19.02; NOVA; In this animated interactive, see how the motion of the Earth creates inertial forces that combine with the gravity of the moon and sun to produce ocean tides on our planet. Explore how the relative motion of the Earth, moon, and sun combine to produce ocean tides.