Reproduction Humans n Sexual Reproduction Involves parents Increases

Reproduction

Humans n Sexual Reproduction ¨ Involves _____ parents ¨ Increases genetic _____

REVIEW n Gametogenesis is the formation of male and female ________. ¨ Female = ______ ¨ Male = _______ n Occurs by the process of _____ ¨ Reduces chromosome # by ______

Male Reproductive System

Male Reproductive System n Testes ¨ Male gonads ¨ Makes sperm ¨ Contained in scrotum

Male Reproductive System n Vas Deferens ¨ Carries sperm from testes to urethra ¨ When this tube is cut, it is called a vasectomy

Male Reproductive System n Prostate Gland ¨ Secretes a fluid that nourishes sperm and produces semen ¨ Seminal Vesicle makes fluid that contains proteins, enzymes, fructose, mucus, vitamin C and other chemicals.

Male Reproductive System n Penis ¨ Deposits sperm into female reproductive tract

Female Reproductive System

Female Reproductive System n Ovaries ¨ Female gonads ¨ Make eggs (contained in follicles) ¨ Once a woman stops making viable eggs, she is no longer fertile and has gone through menopause n Fun Fact: A girl is born with about 400, 000 immature ova already formed in the ovaries. Only about 400 will mature into eggs in her lifetime.

Female Reproductive System n Fallopian Tubes/Oviduct ¨ Egg is pulled into oviduct by cilia ¨ Site of fertilization

Female Reproductive System n Uterus (womb) ¨ Muscular organ where fertilized egg implants and develops ¨ Cervix is opening to uterus n It dilates during birth

Female Reproductive System n Vagina ¨ Passageway ¨ Birth canal for sperm

Female Reproductive System n Menstrual Cycle ¨ Begins between ages of 10 -14 ¨ A mature egg is released from follicle in ovary every 27 -30 days

Female Reproductive System n Menstrual Cycle (continued) ¨ 4 Stages n 1. Follicle Stage ¨ n 2. Ovulation ¨ n Follicle bursts & egg is released 3. Corpus Luteum Stage ¨ n Egg matures in ovary Hormones cause progesterone to be made, which stimulates thickening of uterine wall 4. Menstruation ¨ Shedding of uterine wall (if fertilized egg is not present)

Fertilization Egg and Sperm meet in oviduct n Zygote is formed n Zygote undergoes mitosis (cleavage) and becomes embryo n

Development 1. Zygote n 7. Blastula n 11. Gastrula n

Gastrula Ectoderm-Skin and Nervous System Mesoderm-Muscles and Heart Endoderm-Digestive Tract and Respiratory System

Development n Twins ¨ Identical Twins: 1 egg and 1 sperm n Fertilized egg splits n ¨ Fraternal n Twins: 2 eggs and 2 sperm

Development Once the zygote travels to the uterus, it implants itself in the uterine wall. n The placenta provides an exchange of materials between the mother and embryo. n ¨ Placenta cord is connected to embryo by umbilical

Development

External Fertilization/Development n In fish, external fertilization and development

Internal Fertilization/External Development n Frogs and Birds

Chicken Egg Anatomy

Developing Chicken Embryo

Asexual Reproduction n Mitosis produces exact copies n Involves 1 “parent”

Types of Asexual Reproduction Binary Fission n Budding n Sporulation n Regeneration n Parthenogenisis n Vegetative Propogation n

Binary Fission

Budding

Sporulation

Regeneration

Parthenogenesis n Certain organisms can reproduce without fertilization ¨ Ex. Bees, worms, snails, etc.

Vegetative Propagation n Plants (aka vegetables) can reproduce new offspring without fertilization ¨ Runners ¨ Bulbs ¨ Tubers ¨ Cuttings ¨ Grafting

Runners n Stems grow out of the existing stems

Bulbs n Bulbous root is underground and stores food and sprouts a new plant

Tubers n Underground root that has stored starch which is used to feed new growths

Cuttings and Grafting n Cuttings and graftings are “artificial” ¨ Cuttings use a part of the root, stem or leaf to re-grow a new plant. ¨ Graftings take a cutting from one plant and attaches it to a different plant

Cuttings

Grafting

Grafting