1. Meiosis and
Sexual Reproduction

2. Asexual Reproduction First 2 billion years Advantages:
One parent (quick and easy)
Increase numbers quickly
Favorable in stable environment
Disadvantages:
Offspring identical (clones)
Slow evolution/ less diversity (extinction)

3. Fiss ion Division into two or more Equal= binary
Can be along any plane

4. Budding Budding Internal Bud gemmule external
Group of cells on parent develops into new individual
Internal
Bud
gemmule
external

5. Frag men ta tion
Body parts regenerate

6. Parthenogenesis Queen bee “Virgin birth”
Egg develops without fertilization- some diploid/ some haploid
Uncommon- role in social organisms
Queen bee

7. Sexual Reproduction Gametes produced (sperm and ova) Advantages:
Genetic diversity (withstand environmental pressure)
Disadvantages:
Complicated-- time, energy requirement
“Cost of meiosis”-- only half genes passed
Wastage in the production of males

8. Human Karyotype: 46 chromosomes!
Autosomes
Sex Chromosomes
Human Karyotype: 46 chromosomes!

10. Polyploidy

13. animation

16. Down's Syndrome: 47 chromosomes with 3 #21 chromosomes.
Triple-X Syndrome: 47 chromosomes caused by 3 X chromosomes.
Klinefelter's Syndrome: 47 chromosomes caused by 2 X chromosomes and 1 Y chromosomes.
Turner's Syndrome: 45 chromosomes with 1 X chromosome (caused by the absence of one of the X chromosomes or a Y chromosome).

17. 2004- Question 1
Meiosis reduces chromosome number and rearranges genetic
information.
(a) Explain how the reduction and rearrangement are
accomplished in meiosis.
(b) Several human disorders occur as a result of
defects in the meiotic process. Identify one such
chromosomal abnormality; what effects does it have on
the phenotype of people with the disorder? Describe
how this abnormality could result from a defect in
meiosis.
(c) Production of offspring by parthenogenesis or
cloning bypasses the typical meiotic process. Describe
either parthenogenesis or cloning and compare the
genomes of the offspring with those of the parents.