1. Reproduction in Animals
• Important to the survival of a species
• May increase genetic variation
• Two Types of Reproduction:
– Asexual – one parent, offspring are clones
• Bacteria, plants, amoebas, and simple organisms
– Sexual – joining of gametes (egg/sperm)
increases variation
• Some plants, many animals
• Reproductive strategies changed as
animals evolved from living in water to
living on land

2. Reproduction and Development in Animals
Fertilization Requirements Advantages Disadvantage Examples
s
External - Large # of Parents don’t
Less chance
Frogs, coral,
- gametes join gametes need to be in sponges,
outside of body - Water
of fertilization
the same most fish
place
- Specialized - chance of
Internal fertilization
Parents must Birds, reptiles,
- gametes join organs (ie: be close mammals,
penis) - Lower # of
inside of body together some fish
- Mating rituals gametes
Development Requirements Advantages Disadvantage Examples
s
External Water or Shell No parental Frogs, many
to prevent Low chance
- growth of care needed fish, reptiles,
offspring occurs drying out of survival
birds
outside of parents’
body
Internal Specialized chance of
- Growth of offspring Pregnancy is Mammals,
organs support
offspring occurs
survival demanding some sharks &
inside of parent’s developing
some snakes
body egg ( uterus,
placenta)

3. Reproductive Adaptations in Animals
Amplexus in Frogs Eggs prevent reptiles
from drying out on land
Specialized
organs in
damselflies