For those wanting to know what the new Snapchat emoji symbols mean, there is several different things that they repersent and these emojis have replaced the âBest Friendsâ feature with Friend Emojis smilies.
(plural tetrads) 1  A group of four things. ( 2 chemistry) A tetravalent atom or radical. ( biology) Two pairs of sister chromatids (a dyad pair) aligned in a certain way and often on the equatorial plane during the meiosis process.
Meiosis I. Meiosis I has four phases just like mitosis (Prophase, Metaphase, Anaphase, and Telophase) with some small differences. 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.