1. Animal Reproduction Sexual & Asexual By Diana L. Duckworth Rustburg High School Campbell County

2. Asexual Reproduction Budding – small part of parent’s body grows into new organism Genetically identical clones http://johnson.emcs.net/life/images/anemone.bmp http://www.microscope-microscope.org/gallery/Mark- Simmons/images/hydra2.jpg

3. Asexual Reproduction Regeneration – parent separates into two or more pieces & each piece forms new organism –In some instances just a new part grows –Sponges, sea stars, jellyfish, planaria –Also be clones http://www.starfish.ch/reef/echinoderms.html

4. Asexual Reproduction Parthenogenesis – growth & development of embryo without fertilization by male Population all female Many insects; lizards, salamanders, fish, turkeys http://www.nova.edu/ocean/ghri/bbc_virginshark.html

5. Sexual Reproduction – gametes from opposite sexes unite Species with sexual reproduction are said to be dioecous – separate sexes Often exhibit distinct sexual dimorphism – males and females look different Sperm (male gamete) formed by meiosis in testes Eggs (female gamete) formed by meiosis in the ovary http://civilliberty.about.com/od/historyprofiles/ss/news080406_2.htm

6. Mating Mating – male & female join together to ensure fertilization; not essential to sexual reproduction http://www.hickerphoto.com/elephants-mating-205-pictures.htm http://www.torreypine.org/animals/reptiles.html http://www.eeb.cornell.edu/agrawal/photos/milkweed %20fauna/pages/Tetraopes%20tetrophthalmus%20m ating.html http://www.snakesandfrogs.com/scra/lizards/greenanole.htm

7. External Fertilization Males & females release sperm & eggs into the environment – sperm & egg join outside the body –Males & females may come into close proximity –Eggs & larvae develop outside the body –Many gametes produced; many zygotes formed –Usually aquatic http://www.biol.andrews.edu/everglades/organisms/Invertebr ates/marine_inverts/Arthropoda/Atlantic%20Horseshoe%20 Crab/atlantic_horsehoe_index.htm

8. External Fertilization – e.g. Salmon http://www.mass.gov/dfwele/dfw/dfwstksl.htm http://escoberphoto.co m/travel/katmai.html http://www.biology-blog.com/blogs/archives/Biology-blog/520525028-Feb-14-2008.html

9. Internal fertilization Joining of sperm & egg inside the body after mating –Ensures selection of mate (not random); promotes diversity –Parents protect and care for young –Does not require water; can occur on land –Less sex cells produced; increases probability of successful reproduction –Common in birds, reptiles & mammals

10. Internal fertilization; external development After fertilization, larvae (embryo) are released & development occurs outside female body Example: Barnacles http://www.microscopy- uk.org.uk/mag/indexmag.html?http://www.microscopy- uk.org.uk/mag/artjan99/barnac.html http://getfile.ucoz.com/load/9-1-0-578

11. Internal fertilization & development Females put large amounts of energy into development of embryo – very few in litter or clutch – different schemes Eggs in “shell” are laid and either abandoned or nurtured in nest http://www.nps.gov/pais/naturescience/reptiles.htm http://crd.dnr.state.ga.us/content/displaycontent.asp?t xtDocument=542 http://www.fws.gov/archiecarr/photos/index.html

12. Various levels of parental care http://animals.nationa lgeographic.com/ani mals/photos/baby- animals/american- crocodile- baby_image.html http://www.flmnh.ufl.edu/cnhc/potm-mar99.html

13. Internal fertilization & internal development of eggs; followed by live birth http://earth- advocates.org/index.php?option=com_content&t ask=blogcategory&id=22&Itemid=46 http://www.pacfish.org/sharkcon/documents/gruber.html

14. Internal fertilization, internal development of embryo to fetus, live birth http://www.abc.net.au/science/scribblygum/march2006/ http://www.seahorse-australia.com.au/pages/seahr_biology.html In seahorses, eggs are deposited in the male where they are fertilized and develop. Babies born live.

15. In most species, it is the female who carries the developing fetus to birth… http://www.scienceclarified.com/El-Ex/Embryo-and-Embryonic-Development.html http://www.sciencedaily.com/releases/2008/04/080410184336.htm http://humangenetics.suite101.com/article.cfm/three_parent_embryo_mtdna

16. Hermaphrodites Organisms that change sex in order to reproduce Crepidula fornicata – a snail http://www.opalesurfcasting.net/la_faune_aquatique/la_crepidule_-_crepidula_fornicata_article1202.html?var_recherche=+bar http://www.dkimages.com/discover/Home/Animals/Inv ertebrates/Molluscs/Gastropods/Marine- Snails/Crepidulidae/Atlantic-Slipper/Atlantic-Slipper- 1.html