Cell Reproduction

Cell Reproduction – Meiosis 4.5 Body cells or ________ cells are _______, which means they have ___ sets of chromosomes. One set came from the _______ parent and the other came from the ________ parent. somatic diploid 2 male female

Diploid Cells Since diploid cells have 2 sets of chromosomes , they are represented by _____. In humans, this number is ____. Somatic diploid cells reproduce to make ____ identical copies of themselves in the process called ________. Somatic cell reproduction 2n 46 2 Humans mitosis

Haploid Cells Cells with only 1 set of chromosomes are said to be ________. These cells are represented by ____. In humans, this number is ____. Only the sex cells or ________ of a multicellular organism are haploid. haploid n 23 gametes

Meiosis (not mitosis) The gametes of an organism are produced in a type of cell division called _________. Meiosis occurs in the _________ of the cell cycle. M = mitosis for somatic body cells M = meiosis for making gametes meiosis M phase

Meiosis During meiosis, a nucleus undergoes ___ rounds of division. A diploid cell becomes ____, _______ daughter cells. 2 4 haploid

Meiosis in Humans Meiosis occurs in the reproductive organs. Testes in males (sperm) Ovaries in females (egg/ovum) Diploid germ cell In testicle or ovary Haploid sperm or egg cells

Meiosis Animation http://highered.mheducation.com/sites/0072495855/student_view0/chapter3/animation__how_meiosis_works.html

Comparing Mitosis & Meiosis Purpose of Process Growth & Repair Formation of gametes Type of cells it occurs in Somatic Germ cell in testes Germ cell in ovary Chromosome number in parent cell 2n (46) Number of times the DNA replicates 1 Number of nuclear/cellular divisions 2 Number of daughter cells produced 4 Chromosome number in daughter cells n (23) Daughter cells identical or different from parent cell identical different When synapsis and crossing over occurs never Prophase I

Memory Aid miTosis mainTains the chromosome number (2n2n) meiOsis lOwers the chromosome number from two sets to one set (2nn)