Cytokinesis Cytoplasm Divides 2 Identical daughter cells form with the SAME number of chromosomes as parent cell Occurs during Telophase
MITOSIS END RESULT: Produces 2 Genetically Identical Diploid Body (Somatic) Cells
Cytokinesis ANIMAL CELL PLANT CELL
MEIOSIS REPRODUCTION OF SEX CELLS PRODUCES 4 GENETICALLY DIFFERENT HAPLOID GAMETES
Interphase Cell Grows & Prepares for Division DNA is Replicated
Meiosis I Prophase IMetaphase I Anaphase ITelophase I
Meiosis II Prophase IIMetaphase II Anaphase IITelophase II 2 Stages of Division HAPLOID4
Crossing Over Synapsis/Tetrad = Homologous Chromosomes Pair Up & Cross Over Crossing Over begins during Prophase I & ends during Anaphase I Crossing Over is important because – It increases Genetic Diversity – It ensures that all cells produced during meiosis are Different – It Unlinks genes
Homologous Chromosomes Pair Up & Cross Over Homologous Chromosomes Line Up In The Middle (double line)
Meiosis I Homologous Chromosomes Separate
Chromosomes Line Up in the Middle (single line) Sister Chromatids Separate Spindle Reforms & Chromosomes Attach
Meiosis II Produces 4 Genetically Different Haploid Gametes (Sex Cells)
1 1 ovum (egg) produced 4 4 sperm produced Fertilization Zygote
Karyotype: Male or Female?
Human Gametes normally have 23 chromosomes. Human Body Cells normally have 46 chromosomes (23 pairs).
What is this disorder called? Down’s Syndrome OR Trisomy 21 This is caused by Nondisjunction. Nondisjunction can occur during Anaphase I OR Anaphase II of meiosis if the chromosomes do not SEPARATE correctly.
Stage of Meiosis = Anaphase I Stage of Meiosis = Anaphase II Too Many Chromosomes
Chromosomes Line Up in the Middle/Equator Homologous Chromosomes Line Up in the Middle/Equator Crossing Over Sister Chromatids Separate Homologous Chromosomes Separate Haploid Diploid 2 Identical Body Cells 4 Genetically Different Gametes (sex cells)