1. Adaptations in Fertilization and Development of Young
External Fertilization: Reproduction in many cold-blooded vertebrate animals, such as fish and amphibians.
The gametes fuse outside the body of the female.
Usually large numbers of eggs are required to ensure survival of the species.

2. Amphibians
External Fertilization
External Development

3. External Development: Overproduction of Eggs

4. Fish: External Fertilization & external development

5. Internal Fertilization
Reproduction in most warm-blooded vertebrate animals is characterized by internal fertilization.
The gametes fuse in the moist reproductive tract of the female.

6. Internal Fertilization/ External Development
BIRDS
PARENTAL CARE
Increases Survivorship
Of offspring

7. Reptiles Internal Fertilization External Development
Little to No Parental Care
once eggs are laid

8. External Development
External development occurs outside of the female’s body.
In Water: The eggs of many fish and amphibians are fertilized and develop externally in an aquatic environment.
On Land: Eggs of birds, many reptiles and a few mammals develop externally on land after internal fertilization.
The developing embryo’s source of food is the yolk.

9. Nonplacental Mammals:Monotremes
Egg-laying mammals
Spiny Anteater
Duckbill Platypus
Lay leathery eggs (like reptiles), then feed young with milk from mammary glands

10. Nonplacental / Pouched Mammals
Marsupials : embryo develops internally, then Immature fetus crawls into Mother’s Pouch where it attaches to the
Mammary gland
And completes
Development in the
pouch.
Kangaroo
Opossum
Koala

11. Internal Development: Placental Mammals
Amniotic Sac
Placenta
Umbilical cord
Maternal
Portion of
Placenta
Fetal portion
Of Placenta
Uterus
Amnion
Umbilical Cord
Maternal
artery
Umbilical
Artery & Vein
Maternal
vein

12. Placental Mammals
Most mammals, including humans, have a specialized structure called the placenta, that provides for nutrient, gas, and waste exchange between the mother and the offspring.
The baby is attached to the placenta by an umbilical cord
The umbilical cord contains blood vessels, connecting baby’s circulatory system to the capillaries of the placenta

13. Placental Mammals Internal fertilization And development
Increases the chances
Of survival of young
Mammals also provide
Milk and parental care
Also increasing
Survivorship
As a consequence,
Mothers birth fewer
offspring

14. The Ins and Out of Eggs

15. Egg: Adaptation for external development
Embryo
Allantois
Amnion
Chorion
Yolk Sac
Shell

16. External VS Internal Development

17. Angiosperms: Flowering Plants
Perfect Flower has both
Male and female reproductive
Organs.
Gamete production (meiosis)
Occurs in the Anther (pollen),
And the Ovary (ovules)
Stamen
pistil
Stigma
Anther
Style
filament
Ovary
Petal
Ovule
Sepal

18. Pollination: Insects, birds, wind and Other Critters
Example of Mutualism