1. AP Biology
Meiosis Part 1

2. Interphase

3. (before chromosome replication).
MITOSIS
MEIOSIS
Parent cell
(before chromosome replication)
Chiasma (site of
crossing over)
MEIOSIS I
Propase
Prophase I
Chromosome
replication
Chromosome
replication
Tetrad formed by
synapsis of homologous
chromosomes
Duplicated chromosome
(two sister chromatids)
2n = 6
Chromosomes
positioned at the
metaphase plate
Tetrads
positioned at the
metaphase plate
Metaphase
Metaphase I
Anaphase
Sister chromatids
separate during
anaphase
Homologues
separate
during
anaphase I;
sister
chromatids
remain together
Anaphase I
Telophase
Telophase I
Haploid
n = 3
Daughter
cells of
meiosis I 2n 2n
MEIOSIS II
Daughter cells
of mitosis n n n n
Daughter cells of meiosis II
Sister chromatids separate during anaphase II

4. Parent to offspring

5. Mom and Dad’s DNA contribution The egg surrounded by sperm.

6. Locus (Gene locations on chromosomes)

7. Asexual reproduction (One parent) See the bud on the side… that is the “new” organism to be.

8. Sexual Reproduction (Two parents)

9. Lifecycles of organisms
Key
Haploid
Diploid
Haploid multicellular
organism (gametophyte)
Haploid multicellular
organism
Gametes n n
Mitosis n
Mitosis
Mitosis n
Mitosis n n n n n n
Spores n
MEIOSIS
FERTILIZATION n
Gametes
Gametes n
MEIOSIS
FERTILIZATION
MEIOSIS
FERTILIZATION
Zygote 2n 2n 2n 2n
Diploid
multicellular
organism
(sporophyte)
Zygote 2n
Diploid
multicellular
organism
Mitosis
Mitosis
Zygote
Animals
Plants and some algae
Most fungi and some protists

10. Female (XX) Karyotype (Remember… “kary” means “nucleus”)

11. Male (XY) Karyotype

12. Germ cells at fertilization