Aim #54: What are the different ways organisms carry out reproduction? Date: February 22, 2016 Aim #54: What are the different ways organisms carry out reproduction? HW: Asexual and Sexual Reproduction Practice Worksheet Unit 6 Test Thursday 2/25 (period 5) & Friday 2/26 (periods 1 and 7) Human Phys. Unit 7a Packet due next Friday (March 4th) Do Now: Warm-Up Notebook Date Title of Activity Page # 2/22 Prophase (Review) 94

Aim #54: What are different ways organisms carry out reproduction?

Asexual vs. Sexual Reproduction 1 Parent Produce Offspring 2 Parents Offspring are identical Critical for survival of the species Offspring are not identical Bacteria, Amoeba, Body Cells Humans, Dogs Asexual Reproduction Sexual Reproduction

The union of the egg and sperm cells producing a diploid zygote Fertilization The union of the egg and sperm cells producing a diploid zygote

1) Types of fertilization a) External Fertilization Egg and sperm unite OUTSIDE the body b) Internal Fertilization Egg and sperm unite INSIDE the body of the female

2) Characteristics of External Fertilization (outside the body) In water Many egg and many sperm Due to lack of protection and a harsh environment Examples: fish and amphibians

3) Characteristics of Internal fertilization (inside the body, moist environment of the female) Mostly on land Fewer eggs Still many sperm Examples: land animals, sharks, and lobsters

4) What is parthenogenesis? Development of an unfertilized egg into an adult Some insects like aphids Type of asexual reproduction

Parthenogenesis Videos History Channel- Parthenogenic Komodo Dragons (~ 2 minutes) https://www.youtube.com/watch?v=G41EANkcMvg Reproducing Without a Male- Parthenogenesis (~4 minutes) https://www.youtube.com/watch?v=dNoY9ribw4A

5) Two types of Development: a) External Development Development of offspring takes place OUTSIDE the body b) Internal Development Development of offspring takes place INSIDE the body

External development in water Fish and amphibians Yolk in egg is source of food O2 diffuses in from water Wastes diffuse out Little or no care from parents Survival rate is low

External development on land Yolk in egg is source of food Better survival rate Fewer eggs Birds and reptiles

6) How is the bird embryo adapted for external development on land? Chicken Egg Large yolk: allows embryo to develop more fully before hatching Shell: protection Chorion: lines the shell and aids in gas exchange between embryo and environment

Allantois: exchange of gases and waste Amnion: contains amniotic fluid for protection from shock Yolk sac: penetrated by blood vessels that transport food to embryo

7) What is Internal Development? Involves growth of the embryo within the body of the parent High survival rate

Internal Placental Umbilical cord: connects fetus with placenta Placenta: organ rich in blood vessels of mother and embryo Attached to wall of uterus Allows movement of nutrients, oxygen and carbon dioxide by diffusion and active transport

Internal Non placental Marsupials: pouched mammals Internal development without a placenta and attachment Embryo gets food from yolk in egg Born before development is complete Completes development in pouch on outside Mammary glands are source of nutrients in pouch

Internal Nonplacental Internal fertilization but young only partially develop internally Born very underdeveloped Spend the second part of development in a pouch on their mothers Kangaroos are the most famous marsupial

Comparison of Development Fish External Many Little/none Amphibian Reptile Internal Fewer Little Birds Yes Mammals Few Fertilization Development # of eggs Parental Care