1. pengel@aacps.org1 Reproduction in Mammals

2. pengel@aacps.org2 Overview Characteristics of Mammals Types of Mammalian Reproduction –Monotremes –Marsupials –Placental Summary

3. pengel@aacps.org3 Sexual Reproduction Review Few offspring Genetic variation 2 parents produce haploid gametes Gametes fuse to produce offspring Offspring have characteristics of both parents, but are not identical to each other or to parents Uses meiosis to produce gametes

4. pengel@aacps.org4 Characteristics of Mammals Warm-blooded Have hair Produce milk to nourish young High metabolic rates Single bone in lower jaw Three middle ear bones http://www.ucmp.berkeley.edu/mammal/mammal.html

5. pengel@aacps.org5 Monotremes Three living monotremes –Duckbilled platypus –2 species of Echidna (spiny anteater) http://www.ucmp.berkeley.edu/mammal/monotreme.html Echidna. Photo by Dr. Lloyd Glenn Ingles © 2001 California Academy of Sciences.

6. pengel@aacps.org6 Monotreme Reproduction Monotremes lay eggs incubated by parents, and nourish underdeveloped young with milk, but have no nipples. Special structures –Eggs, milk, but no nipples encarta.msn.com/media_ 461534650/Platypus.html

7. pengel@aacps.org7 Marsupials Pouched Mammals Some examples are: –Kangaroos, Koalas, Wombats, Red Kangaroo. Photo by Gerald and Buff Corsi, © 2002 California Academy of Sciences. Wombat. Photo © 2005 Sharon Chester www.kidcyber.com.au/ IMAGES/pouch%20baby.jpeg

8. pengel@aacps.org8 Marsupial Reproduction Marsupials give birth to live young Offspring are under- developed and continue to grow in pouch, attached to nipple Nourished by milk Special structures –Nipples –Pouch http://www.wfcr.org/OLD_WWW/opossuminfo.html

9. pengel@aacps.org9 Placental Mammals (Eutheria) Most mammels reproduce with placenta. A few examples are: - Giraffe, Monkeys, Tiger, Cats, Dogs, Elephants, Humans, etc. Yellow Baboon. Photo by H. Vannoy Davis, © 2002 California Academy of Sciences. encarta.msn.com/medias_ 761561349/Mammal.html

10. pengel@aacps.org10 Placental Reproduction Placental mammals give birth to live young Young develop in uterus and are nourished by the placenta Long gestation period Nourished by milk through nipples after birth

11. pengel@aacps.org11 Placental Special Structures Special structures –Uterus –Placenta –nipples

12. pengel@aacps.org12 Quick Review Mammals use sexual reproduction to produce offspring.