Animal Reproduction and Development

Remember: types of fertilization:

•  External: sperm and egg meet in water outside the female ex. fish

•  Internal: sperm and egg meet inside the female ex. humans

•  List more examples….

Types of development:

1.  external: occurs outside the female ex. 2.  Internal: occurs inside the female ex.

External Development Ex. Eggs of fish, amphibians fertilized externally in water. • Many are produced with the hope

that some survive

External development (con’t): • Less care parents provide, more eggs required to guarantee survival of some.

•  External development on land occurs in reptiles, birds, and Perry

•  Eggs have hard shell for protection, and moisture and food inside to help feed the embryo

•  Yolk: food for the developing baby •  Amnion: (egg white) fluid for

protection from shock

Internal development •  Internal fertilization and

development occur within mother. •  Fewer offspring produced • More parental care

•  Placenta is the link between mom and baby- where exchange of food, oxygen, waste, water take place.

•  Drugs and alcohol can cross to the baby

http://embryology.med.unsw.edu.au/Notes/images/placenta/plMembraneW450.jpg

•  Umbilical cord attaches embryo to placenta; belly button

•  Carries nutrients and oxygen into the baby and wastes and CO2 out

•  Amnion of placental mammals provides watery environment - protects against shock.

http://www.udel.edu/Biology/Wags/histopage/colorpage/cfr/cfr.htm

Early development •  Fertilization makes a zygote •  Zygote undergoes mitosis to grow

http://embryology.med.unsw.edu.au/wwwhuman/Stages/Images/Cst800.jpg

Early development Zygote ! tissues ! organs ! organ systems

https://www.youtube.com/watch?v=LcgXN5UAMOQ

Write  down  2  observa0ons  as  you  watch  the  videos:  

This ball of cells will become:

Zygote ! ball of cells! all the parts of a human! (ex. heart, eyes, muscles, bone, etc.)

-hormones from the endocrine system regulate this ex. growth hormone -different genes are turned on at different times to make this happen

What is a life cycle diagram?

What  is  happening  in  this  diagram?    List  4  things  you  see.    

Add  mitosis,  meiosis,  fer0liza0on,  zygote,  and  development  to  this  diagram.      

Where  do  hormones  fit  in?  

Life cycle of a frog

•  Frogs are amphibians •  Amphibians spend part of their life in water

(tadpoles) and part on land (frog) •  Metamorphosis: is when the tadpoles

change into a frog

•  Watch video and list •  Two observations

Life cycle of a frog

Life cycle of a butterfly

•  Most insects go through metamorphosis like a butterfly

•  This is complete metamorphosis

•  Watch the video and write down 2 observations

Some insects undergo incomplete metamorphosis

•  They skip some stages!

•  Watch the video and write down two observations

Dragonfly life cycle

Housefly (complete metamorphosis)

Life cycle of a liver fluke

•  What is a liver fluke? A parasite •  Parasite: causes infection in humans or

animals •  This one infects the liver

•  Watch the video and write down 2 observations: How does it affect farmers?

Life cycle of a liver fluke

Life cycles:

•  1. generic •  Human •  Frog •  Butterfly •  Housefly •  Liver fluke •  Flower and seed •  Mutations- what are they?