Cell Division Cell Division Questions to consider Where

Cell Division

Cell Division Questions to consider… Where? Why? How?

Cell Division • Eukaryotic cells utilize two types of cell division: • mitosis • meiosis Mitosis in everything else Meiosis in sexual reproduction.

Why Divide? • To replace dead or dying cell • To produce more cells to enlarge the organism • Reproduction

Binary Fission • asexual reproduction used by most prokaryotes and protists • Results in the reproduction of a livingcellby division into two equal or nearequal parts.

BINARY FISSION

SUMMARY OF MITOSIS PARENT CELL GROWTH

SUMMARY OF WHAT THE DNA DOES DURING MITOSIS

DNA in Mitosis Chromosome duplication Centromere Sister chromatids Chromosome distribution to daughter cells

DNA Replication during Mitosis • DNA genes CHROMOSOME • Count number of CENTROMERES • Sister chromatids: copied chromosomes attached at centromere

DNA Replication during Mitosis • KARYOTYPE: picture of chromsomes arranged into pairs • Humans have 23 pairs (46 total) chromosomes • http: //en. wikipedia. org/wiki/List_of _number_of_chromosomes_of_va rious_organisms

DNA Replication • The Watson-Crick model of DNA structure suggested a mechanism for its replication – DNA strands separate – Enzymes use each strand as a template to assemble new nucleotides into complementary strands A T C G G C G A T A T Parental molecule of DNA A C C A Nucleotides Both parental strands serve as templates T A T G C G C G C T A T A T A Two identical daughter molecules of DNA