Fertilization • Sperm nucleus enters the egg and moves to the egg nucleus. The 2 nuclei join together and then form a zygote.
External Fertilization*outside the body • Animals that breed in the water • Many hazards in the environment • Sperm and egg may not meet • Eggs or offspring may be eaten • May die due to environmental conditions • Temperature • Oxygen level
Large number of sperm and egg are released to overcome hazards • Hormones control behavior to have sperm and egg released at the same time.
Internal Fertilization*within the female body • Land animals • Some aquatic animals • Shark • Octopus
Requires specialized sex organ to carry sperm to body of female • Watery environment needed for sperm to swim to the egg
After fertilization, zygote is enclosed in a protective shell and released OR remains and develops in female body Zygote Turtle laying eggs
Internal Fertilization • Fewer eggs needed • Well protected • Increased chance of fertilization Parthenogenesis – development of unfertilized egg into an adult.- Bees & Wasps
This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com Is home to well over a thousand powerpoints submitted by teachers. This a free site. Please visit and I hope it will help in your teaching