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.
Physiology. Definition. noun. (1) A branch of biology that deals with the functions, mechanisms, and activities of organisms at the cellular or organ system level.(2) The biological processes and functions of the parts of an organism. Supplement. Physiology is a broad sub-field in biology.hysiology. Definition. noun. (1) A branch of biology that deals with the functions, mechanisms, and activities of organisms at the cellular or organ system level. (2) The biological processes and functions of the parts of an organism. Supplement. Physiology is a broad sub-field in biology.