1. Connect! Where do embryos of the pictured organisms develop? Where do embryos of the pictured organisms develop?

2. Where Embryonic Development Occurs Embryonic development can occur externally or internally. A. EXTERNAL EMBRYONIC DEVELOPMENT: occurs outside the female’s body can occur in water or on land

3. 1. In Water The eggs of many fish and amphibians are fertilized externally and develop externally. The developing embryo’s source of food is the yolk stored in the egg.

4. 2. On Land The eggs of many birds and (and a few mammals) develop externally on land after internal fertilization. Again, the developing embryo’s source of food is the yolk. Adaptations of animals that develop on land are a shell which provides protection and prevents water loss.

6. Chunk Questions What are the two types of development? What are the two types of development? Define “external development”. Define “external development”. Where does it occur? Where does it occur? What type of fert and dev do amphibians and fish use? What type of fert and dev do amphibians and fish use? What is the function of the yolk? What is the function of the yolk? What type of fert and dev do birds use? What type of fert and dev do birds use? What is an adaptation for land external development? What is an adaptation for land external development? What functions does it serve? What functions does it serve? Why are duckbill platypuses and spiny anteaters unusual mammals? Why are duckbill platypuses and spiny anteaters unusual mammals?

7. B. INTERNAL EMBRYONIC DEVELOPMENT involves the growth of the embryo inside the body of the parent There are 2 types of internal development: placental & marsupial 1. Placental Mammals These mammals have internal fertilization. The embryo develops internally within the uterus.

8. Pass folder with photo of cow uterus around, for those interested in looking… Pass folder with photo of cow uterus around, for those interested in looking…

9. Placental Mammals have placentas! The eggs of mammals have very little yolk and therefore are very small. These eggs do not need a lot of yolk bc the placenta exchanges nutrients, wastes, and respiratory gases btwn the mother and the embryo by active transport and diffusion. human egg – size of sharp pencil point

11. There is NO direct connection btwn maternal and embryonic blood. An umbilical cord, containing blood vessels, attaches the embryo to the placenta. placenta Umbilical cord

13. Notice that blood of embryo and mother do NOT mix! So how does exchange of materials occur?

15. Use this diagram to help label the diagram in your notes. Use this diagram to help label the diagram in your notes. ovary uterus amnion embryo oviduct placenta cervix vagina umbilical cord

16. Chunk Questions If an organism has internal development, where does fertilization occur? If an organism has internal development, where does fertilization occur? The following questions refer to placental mammals… Where does the embryo develop? Where does the embryo develop? Why are the eggs of placental mammals so tiny? Why are the eggs of placental mammals so tiny? How does the embryo obtain needed nutrients and gases? How does the embryo obtain needed nutrients and gases? How does the embryo get rid of toxic wastes? How does the embryo get rid of toxic wastes? By what process do O 2 and nutrients move into the embryo? By what process do O 2 and nutrients move into the embryo? Explain the connection btwn mother and embryo in the placenta. Explain the connection btwn mother and embryo in the placenta. What does the umbilical cord do? What does the umbilical cord do? So, what actually IS the placenta? So, what actually IS the placenta?

17. 2. Marsupials These mammals also have internal fertilization with internal embryonic development. These mammals also have internal fertilization with internal embryonic development. Internal development occurs without direct nourishment from the mother; instead, yolk is the source of food. Internal development occurs without direct nourishment from the mother; instead, yolk is the source of food. There is NO placenta!

18. The embryo is born prematurely compared to placental mammals and completes its development externally in a pouch. The source of food in this later stage is milk from mammary glands located in the pouch. The embryo is born prematurely compared to placental mammals and completes its development externally in a pouch. The source of food in this later stage is milk from mammary glands located in the pouch. Consider a newborn koala… A newborn koala is approximately the size of a gummi bear. It is born 35 days after conception and immediately crawls into its mother's pouch, where it stays for six to seven months, before taking its first peek out.

19. Let’s look at the development of another marsupial, the kangaroo… Kangaroos have developed a number of adaptations to a dry, infertile continent and a highly variable climate. Kangaroos have developed a number of adaptations to a dry, infertile continent and a highly variable climate. As with all marsupials, the young are born at a very early stage of development after a gestation of 31-36 days. At this stage, only the forelimbs are somewhat developed, to allow the newborn to climb to the pouch and attach to a teat. As with all marsupials, the young are born at a very early stage of development after a gestation of 31-36 days. At this stage, only the forelimbs are somewhat developed, to allow the newborn to climb to the pouch and attach to a teat. In comparison, a human embryo at a similar stage of development would be about 7 weeks old, and premature babies born at less than 23 weeks are usually not mature enough to survive. In comparison, a human embryo at a similar stage of development would be about 7 weeks old, and premature babies born at less than 23 weeks are usually not mature enough to survive.

20. The joey will usually stay in the pouch for about 9 months or (for the Western Grey) 180 to 320 days, before starting to leave the pouch for small periods of time. It is usually fed by its mother until the age of 18 months. The joey will usually stay in the pouch for about 9 months or (for the Western Grey) 180 to 320 days, before starting to leave the pouch for small periods of time. It is usually fed by its mother until the age of 18 months.

21. Examples of marsupials include kangaroos and opossums (only marsupial native to North America) Examples of marsupials include kangaroos and opossums (only marsupial native to North America)

22. Chunk Questions What type of fert and dev do marsupials have? What type of fert and dev do marsupials have? Do marsupials have a placenta? Do marsupials have a placenta? How do the embryos get nourishment? How do the embryos get nourishment? Describe marsupial embryos. Describe marsupial embryos. Name some marsupials. Name some marsupials. What is the gestation period for kangaroos and koalas? What is the gestation period for kangaroos and koalas? How is marsupial development different from placental? How is marsupial development different from placental? How is marsupial development similar to placental? How is marsupial development similar to placental?

23. Image Sources Bunny - oregonjon.wordpress.com/.../ Bunny - oregonjon.wordpress.com/.../oregonjon.wordpress.com/.../ Apple - organic-center.org/.../ripe-red-apple.jpg Apple - organic-center.org/.../ripe-red-apple.jpg Oppossum - 1.bp.blogspot.com/.../s400/oppossum.jpg Oppossum - 1.bp.blogspot.com/.../s400/oppossum.jpg Trout - skywalker.cochise.edu/.../image022.jpg Trout - skywalker.cochise.edu/.../image022.jpg Sea turtle - www.treehugger.com/2008/10/19-week/ Sea turtle - www.treehugger.com/2008/10/19-week/www.treehugger.com/2008/10/19-week/ Ostrich - photos.igougo.com/images/p303673-Oranjestad-O... Ostrich - photos.igougo.com/images/p303673-Oranjestad-O... Kangaroo - www.royalpetclub.com/blog/wp-content/uploads/... Kangaroo - www.royalpetclub.com/blog/wp-content/uploads/...www.royalpetclub.com/blog/wp-content/uploads/ Stink bug eggs - www.edupic.net/.../hem_stink_bug_eggs01.JPG Stink bug eggs - www.edupic.net/.../hem_stink_bug_eggs01.JPG Frog eggs - academic.emporia.edu/sievertg/tadpoles/devo.htm Frog eggs - academic.emporia.edu/sievertg/tadpoles/devo.htmacademic.emporia.edu/sievertg/tadpoles/devo.htm Platypus photo and anteater - www.greenfieldpub.lib.in.us/.../platypus.jpg Platypus photo and anteater - www.greenfieldpub.lib.in.us/.../platypus.jpg Robin eggs www.wbu.com/chipperwoods/photos/robin.htm Robin eggs www.wbu.com/chipperwoods/photos/robin.htmwww.wbu.com/chipperwoods/photos/robin.htm Sea turtle eggs - naturescrusaders.files.wordpress.com/2009/06/... Sea turtle eggs - naturescrusaders.files.wordpress.com/2009/06/... Patchwork platypus - www.olliverlyle.com/.../images/platy5.gif Patchwork platypus - www.olliverlyle.com/.../images/platy5.gif Duckbill cartoon - www.cartoonstock.com/lowres/shr0115l.jpg Duckbill cartoon - www.cartoonstock.com/lowres/shr0115l.jpg Arthur and Baby Kate - http://pbskids.org/arthur/ Arthur and Baby Kate - http://pbskids.org/arthur/http://pbskids.org/arthur/ Placenta diagram – E. Thomas Placenta diagram – E. Thomas Embryo diagram and placenta sketch (modified by E. Thomas) - en.wikibooks.org/.../Reproductive_System Embryo diagram and placenta sketch (modified by E. Thomas) - en.wikibooks.org/.../Reproductive_Systemen.wikibooks.org/.../Reproductive_System Slide 13 and 14– diagrams (modified by E. Thomas) - http://www.mikecurtis.org.uk/biol0image4_2.gif Slide 13 and 14– diagrams (modified by E. Thomas) - http://www.mikecurtis.org.uk/biol0image4_2.gifhttp://www.mikecurtis.org.uk/biol0image4_2.gif Types of marsupials - visual.merriam-webster.com/images/animal-king. Types of marsupials - visual.merriam-webster.com/images/animal-king. Koala with baby - www.itee.uq.edu.au/~adc2010/koala.jpg Koala with baby - www.itee.uq.edu.au/~adc2010/koala.jpg Newborn koala/gummi bear - www.koalajo.com/images/gummibear.jpg Newborn koala/gummi bear - www.koalajo.com/images/gummibear.jpg Joey in pouch - en.wikivisual.com/images/4/4f/Joey_in_pouch.jp, blogs.courierpostonline.com/fishhead/files/20..., Joey in pouch - en.wikivisual.com/images/4/4f/Joey_in_pouch.jp, blogs.courierpostonline.com/fishhead/files/20..., Kangaroo cartoon - www.cartoonstock.com/lowres/ato0120l.jpg Kangaroo cartoon - www.cartoonstock.com/lowres/ato0120l.jpg

24. JFF

25. More JFF!