1. BIOLOGY
Unit 4 Notes:
Types of
Reproduction

2. (1) Types of Reproduction
SEXUAL
ASEXUAL
• Requires 2 parent organisms.
• Requires 1 parent organism.
• Sperm + Egg fertilize one another to form a
Zygote.
• The single organism makes a copy of itself
and divides.
• The offspring are genetically unique from
the parents, but contain a random
combination of parental genes.
• The offspring are genetically identical to the
parent.
• Used by humans, other animals and plants.
• Used by yeast, sponges, and bacteria.
• Pros  Produces genetically different
babies, increasing the survival rate of the
population.
• Cons  Requires a lot of time and effort.
• Pros  Extremely efficient.
• Cons  If the parent has genetic defects /
deficiencies, all of its offspring will also be
“weak”.

4. (2) Types of Asexual Reproduction:
• Binary Fission:
The organism makes an identical copy of itself,
divides and splits in two.
• Budding:
The parent organism develops a small bud off its
side, which develops into an exact copy.

7. (3) Bacteria & Conjugation
• Bacterial Conjugation:
The process by which bacteria exchange extra DNA structures
(called plasmids) which can increase resistance to antibiotics.
• When Does This Happen In Us?
– If you don’t finish a full round of antibiotics…
– This allows a mix of weaker bacteria to survive, along with the more fit
ones (with the plasmids).
– Bacteria can then pass on their extra special DNA.
– This makes more bacteria resistant to your medicine.
• What is the Long Term Concern?
– Some wonder if our overuse of antibacterial body products and
antibiotic medicines could be promoting the evolution of antibioticresistant bacteria.