First off, let's start with the key terms and vocabulary.
Hello class, My name is Professor Pickle. Today we are going to be learning all about Meiosis.
Gametes are a mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote. Haploid means to have a single set of unpaired chromosomes. Diploid means to have two complete sets of chromosomes, one from each parent. Reduction Division is the first cell division in meiosis, the process by which germ cells are formed. In reduction division, the chromosome number is reduced from diploid (46 chromosomes) to haploid (23 chromosomes).
Homologous Chromosomes are chromosome pairs (one from each parent) that are similar in length, gene position, and centromere location. Crossing Over is a process in genetics by which the two chromosomes of a homologous pair exchange equal segments with each other. Sister Chromatids refer to the identical copies (chromatids) formed by the replication of a chromosome. Chromosomes are thread-like structures located inside the nucleus of animal or plant cells. They are made up of protein and a single molecule of deoxyribonucleic acid (DNA).
A Chromatin is the material of which the chromosomes of organisms other than bacteria are composed, consisting of protein, RNA, and DNA The Centromere is the region of a chromosome to which the microtubules of the spindle attach, via the kinetochore, during cell division.
Great Job Class! We are now done with the vocabulary and key terms, Lets study the steps of Meiosis now.
Interphase: Cells undergo a round of DNA replication, forming duplicate chromosomes. (Start of Meiosis) Prophase 1: Each chromosome pairs with its corresponding homologous chromosome to form a tetrad. Metaphase 1: Spindle fibers attach to the chromosomes
Anaphase 1: The fibers pull the homologous chromosomes toward opposite ends of the cell Telophase 1 & Cytokinesis: Nuclear membranes form. The cell separates into two cells.