1. MEIOSIS AND SEXUAL LIFE CHANGES

2. YOU MUST KNOW… THE DIFFERENCES BETWEEN ASEXUAL AND SEXUAL REPRODUCTION
THE ROLE OF MEIOSIS AND FERTILIZATION IN SEXUALLY REPRODUCING ORGANISMS
THE IMPORTANCE OF HOMOLOGOUS CHROMOSOMES TO MEIOSIS

3. YOU MUST KNOW…
HOW THE CHROMOSOME NUMBER IS REDUCED FROM DIPLOID TO HAPLOID THROUGH THE STAGES OF MEIOSIS
THREE IMPORTANT DIFFERENCES BETWEEN MITOSIS AND MEIOSIS
THE IMPORTANCE OF CROSSING OVER, INDEPENDENT ASSORTMENT, AND RANDOM FERTILIZATION TO INCREASING GENETIC VARIABILITY

4. CONCEPT 13.1
OFFSPRING ACQUIRE GENES FROM PARENT BY INHERITING CHROMOSOMES

5. GENES ARE SEGMENTS OF DNA
A LOCUS IS THE LOCATION OF A GENE OF A CHROMOSOME
ASEXUAL REPRODUCTION – SINGLE PARENT, ARISE BY MITOSIS, CLONE
SEXUAL REPRODUCTION – TWO PARENTS, RESULTS IN GREATER GENETIC VARIATION

6. BACTERIA REPRODUCE ASEXUALLY BY BINARY FISSION OR SEXUALLY BY
CONJUGATION
ONE COILED
CHROMOSOME

7. CONCEPT 13.2
FERTILIZATION AND MEIOSIS ALTERNATE IN SEXUAL LIFE CYCLES

8. LIFE CYCLE
THE GENERATION-TO-GENERATION SEQUENCE OF STAGES IN THE REPRODUCTIVE HISTORY OF AN ORGANISM FROM CONCEPTION TO PRODUCTION OF ITS OWN OFFSPRING

9. KARYOTYPE
A PICTURE OF ITS COMPLETE SET OF CHROMOSOMES, ARRANGED IN PAIRS OF HOMOLOGOUS CHROMOSOMES FROM THE LARGEST PAIR TO THE
SMALLEST PAIR
MADE FROM A
HUMAN SOMATIC
CELL

10. HOMOLOGOUS CHROMOSOMES
CONTROL THE SAME INHERITED CHARACTERISTICS
EACH PAIR IS INHERITED FROM EACH PARENT
NONSEX CHROMOSOMES - AUTOSOMES
EXCEPTION- SEX CHROMOSOMES

11. MEIOSIS GAMETES – EGG AND SPERM, HAPLOID CELLS – n
ZYGOTE – FERTILIZED EGG, DIPLOID – 2n
MEIOSIS REDUCES THE NUMBERS OF SETS OF CHROMOSOMES FROM TWO TO ONE
FERTILIZATION RESTORES THE DIPLOID NUMBER

12. CONCEPT 13.3
MEIOSIS REDUCES THE NUMBER OF CHROMOSOME SETS FROM DIPLOID TO HAPLOID

13. MEIOSIS PRECEDED BY THE REPLICATION OF THE CELL’S DNA (INTERPHASE)
FOLLOWED BY TWO STAGES OF CELL DIVISION, MEIOSIS I AND II
RESULTS IN FOUR DAUGHTER CELLS WITH THE HAPLOID NUMBER

14. PROPHASE I
SYNAPSIS OCCURS (JOINING OF HOMOLOGOUS CHROMOSOMES ALONG THEIR LENGTH) FORMING TETRADS
TETRADS UNDERGO CROSSING OVER WHICH INCREASES GENETIC VARIATION
AREAS OF CROSSING OVER FORM CHIASMATA (HOLDS THE HOMOLOGUES TOGETHER UNTIL ANAPHASE I)
CENTRIOLES MOVE AWAY FROM EACH OTHER, THE NUCLEAR ENVELOPE DISINTEGRATES, AND SPINDLE MICROTUBULES ATTACH TO THE KINETOCHORES OF THE HOMOLOGUES

16. METAPHASE I
HOMOLOGOUS PAIRS OF CHROMOSOMES ARE LINED UP AT THE METAPHASE PLATE
MICROTUBULES FROM EACH POLE ATTACH TO EACH MEMBER OF THE PAIR

17. ANAPHASE I
SPINDLES HELP MOVE THE CHROMOSOMES TOWARD OPPOSITE ENDS OF THE CELL
SISTER CHROMATIDS STAY CONNECTED AND MOVE TOGETHER TOWARD THE POLES

18. TELOPHASE I
HOMOLOGOUS CHROMOSOMES MOVE UNTIL THEY REACH OPPOSITE POLES
EACH POLE CONTAINS A HAPLOID SETS OF CHROMOSOMES, WITH EACH CHROMOSOME STILL CONSISTING OF TWO SISTER CHROMATIDS

19. CYTOKINESIS DIVISION OF THE CYTOPLASM
CLEAVAGE FURROW OCCURS IN ANIMAL CELLS
CELL PLATE OCCURS
IN PLANT CELLS
RESULTS IN TWO
HAPLOID CELLS

20. MEIOSIS II NO DUPLICATION OF CHROMOSOMES
PROPHASE II – SPINDLES FORM AND SISTER CHROMATIDS MOVE TOWARD THE METAPHASE PLATE
METAPHASE II – CHROMOSOMES ARE LINED UP ON THE METAPHASE PLATE
ANAPHASE II – CENTROMERES OF THE SISTER CHROMATIDS SEPARATE AND INDIVIDUAL CHROMOSOMES MOVE TO OPPOSITE ENDS OF THE CELL

21. MEIOSIS II
TELOPHASE II – CHROMATIDS HAVE MOVED ALL THE WAY TO OPPOSITE ENDS OF THE CELL
NUCLEI REAPPEAR
CYTOKINESIS – EACH OF THE 4 DAUGHTER CELLS HAS THE HAPLOID NUMBER OF CHROMOSOMES AND IS GENETICALLY DIFFERENT FROM THE PARENT CELL AND THE OTHER DAUGHTER CELLS

22. 3 EVENTS OCCUR DURING MEIOSIS I THAT DO NOT OCCUR DURING MITOSIS
SYNAPSIS AND CROSSING OVER DO NOT NORMALLY OCCUR DURING MITOSIS
AT METAPHASE I, TETRADS ARE POSITIONED ON THE METAPHASES PLATE RATHER THAN INDIVIDUAL REPLICATED CHROMOSOMES AS IN MITOSIS
AT ANAPHASE I, DUPLICATED CHROMOSOMES OF EACH HOMOLOGOUS PAIR MOVE TOWARD OPPOSITE POLES, BUT THE SISTER CHROMATIDS OF EACH DUPLICATED CHROMOSOME STAY ATTACHED. THE CHROMATIDS SEPARATE IN MITOSIS.

23. CONCEPT 13.4
GENETIC VARIATION PRODUCED IN SEXUAL LIFE CYCLES CONTRIBUTES TO EVOLUTION

24. IMPORTANT PROCESSES CROSSING OVER
INDEPENDENT ASSORTMENT OF CHROMOSOMES – IN METAPHASE I, WHEN THE HOMOLOGOUS CHROMOSOMES ARE LINED UP ON THE METAPHASE PLATE, THEY CAN PAIR UP IN ANY COMBINATION
RANDOM FERTILIZATION