1. Sc8 U2.1-2: Mitosis/Meiosis
Unit 2 lesson 1: Mitosis
ROLE OF DNA IN REPRODUCTION
FOUND IN EUKARYOTES’ NUCLEUS
CHROMATIN: NEARLY INVISIBLE THREAD-LIKE DNA – PROTEIN STRUCTURES IN NUCLEUS
CHROMOSOMES: EASILY VISIBLE, COMPACTED CHROMATIN FORMED DURING MITOSIS
CHROMATID: DUPLICATED CHROMOSOMES FORMED DURING MITOSIS
CENTROMERES: STRUCTURE CONNECTING TWO DUPLICATED CHROMOSOMES AT CENTER

2. CELL CYCLE: THE 3 STAGE LIFE CYCLE OF AN EUKARYOTE CELL
INTERPHASE: PERIOD THE CELL IS NOT DIVIDING
THE LONGEST STAGE OF CELL CYCLE, CELL GROW TWICE ITS BEGINNING SIZE
PRODUCES ORGANELLES, PERFORMS LIFE ACTIVITIES
ENDS WITH THE DUPLICATION OF DNA
MITOSIS: 4 PART PROCESS THAT EXACTLY DUPLICATES CELL’S NUCLEUS
CYTOKINESIS: DIVISION OF THE CELL’S CYTOPLASM TAKES PLACE

3. MITOSIS: 4 PART PROCESS THAT EXACTLY DUPLICATES CELL’S NUCLEUS
1. PROPHASE: DOUBLED CHROMATIN CONDENSE INTO CHROMOSOMES
CHROMOSOMES MADE OF 2 CHROMATID HELD TOGETHER BY CENTROMERE
NUCLEAR MEMBRANE DISSOLVES
2. METAPHASE: RELEASED CHROMOSOMES LINE UP IN CELL CENTER
CENTRIOLES FORM THIN SPINDLE FIBERS
SPINDLE FIBERS ATTACH TO CENTROMERES
3. ANAPHASE: SPINDLE FIBERS SEPARATE, PULL CHROMOSOMES TO OPPOSITE SIDES
4. TELOPHASE: 2 NEW NUCLEAR MEMBRANES FORM AROUND CHROMOSOMES

4. CYTOKINESIS: DIVISION OF THE CELL’S CYTOPLASM TAKES PLACE
NEW CELL MEMBRANE DIVIDES CYTOPLASM
CHROMOSOMES UN-COMPACT IN TO CHROMATIN
2 NEW, IDENTICAL DAUGHTER CELLS FORMED

5. Unit 2 lesson 2: Meiosis
CHROMOSOMES: USUALLY FOUND IN HOMOLOGOUS (IDENTICAL) PAIRS
DIPLOID: ONE PAIR OF CHROMOSOMES
HUMANS HAVE 23 PAIRS (46 CHROMOSOMES): ONLY ONE PAIR NOT HOMOLOGOUS
HUMAN SEX CHROMOSOME CONTROL GENDER AND SECONDARY SEXUAL CHARACTERISTICS
XX SEX CHROMOSOME RESULTS IN FEMALE
XY SEX CHROMOSOME RESULTS IN MALE
HALF OF EACH PAIR COMES FROM ONE PARENT’S GAMETE
GAMETES: HAPLOID MALE (SPERM) OR FEMALE (EGG) SEX CELLS
HAPLOID CELLS: CONTAIN ONLY ½ OF THE NEEDED CHROMOSOMES

6. MEIOSIS: CELL DIVISION THAT PRODUCES HAPLOID SEX CELLS
PROCESS RANDOMLY MIXES GENES (DNA CHAINS RESPONSIBLE FOR CHARACTERISTICS)
RESEMBLES MITOSIS DONE TWICE, PRODUCES 4 HAPLOID SEX CELLS WITH MIXED TRAITS
2 STAGE PROCESS
MEIOSIS 1: RESEMBLES MITOSIS, SOME GENES CROSS, MIX
CHROMATIDS REMAINED JOINED BY CENTROMERES
NEW NUCLEAR, CELL MEMBRANES FORM – CELL FORMED NOT IDENTICAL
MEIOSIS II: NO NEW DUPLICATION, MITOSIS-LIKE PROCESS
WITHOUT DNA REPLICATION, RESULTING CELLS HAVE HALF-SET OF CHROMOSOMES
4 HAPLOID SEX CELLS RESULT

7. DOWN’S SYNDROME: GENETIC DISEASE CAUSED BY SEX CHROMOSOMES INSTEAD OF A PAIR
MAY CAUSE HEALTH ISSUES AND LEARNING DISABILITIES
MORE FREQUENT IN FEMALES