There are two types of reproduction 1. Asexual reproduction 2. Sexual reproduction

Asexual Reproduction 1. Mitosis produces two identical cells. 2. Mitosis occurs in body cells.

Types of reproduction A. Binary fission In amoeba B. Budding In yeast

Types of reproduction C. Spores D. Budding in hydra

Types of Reproduction E. Vegetative propagation “baby” plants growing on adult plant Runners

Stages of Mitosis Interphase 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase

Sexual Reproduction 1. Meiosis produces cells with half the number of chromosomes. 2. Meiosis occurs in the gonads, makes gametes = egg or sperm cells

Gametes are… Sperm and Egg cells

Chromosomes Coiled up DNA. You get half from mom and half from dad.

Variation due to meiosis Genes from two parents vs one. Crossing over: Genes get rearranged between chromosomes. Increases genetic variation (also called recombination)

Human Reproduction Ovary = makes eggs Follicle = contains the maturing egg in the ovary

Fertilization Internal fertilization vs external fertilization… Internal… mammals, birds, snakes… External… fish, oysters, coral Vagina = entry point for internal fertilization Uterus = sperm continue up to fallopian tubes Fallopian tubes (oviducts) = where fertilization occurs

Development Internal vs. External development Internal = mammals, some fish and snakes External = fish, frogs, birds, snails…. Uterus= where baby develops Umbilical cord = connects baby to placenta Placenta = connects to uterus. Diffusion of oxygen, nutrients from mom to baby and waste from baby to mom.

Mammary glands: Produce milk for newborn Species [30] [30] Anterior (thoracic)thoracic Intermediate (abdominal)abdominal Posterior (inguinal)inguinal Total GoatGoat, sheep, horse guinea pigsheep horse guinea pig 0022 Cattle0044 Cat2248 Dog [31] 422 or 48 or 10 Mouse60410 Rat62412 Pig66618 proboscidea nsproboscidea ns, primatesprimates 2002 mammals:

Male Reproductive system Produces gametes (sperm) Testes: produce sperm Animal Average number of sperm per ejaculate (in millions) Mouse50 Rabbit280 Human280 Cow3000 Pig8000 A man is considered clinically infertile if his sperm concentration falls below 20 million/ml semen. # Animal Fertile life of sperm Rat14 hours Rabbit30-32 Human24 – 48 Cow28 – 50 Horse144 Bat135 days

Internal Delivery Seminal vesicles = makes semen Prostate gland = also makes semen Semen = fluid containing sperm and nutrients for sperm Vas Deferns = tube that takes sperm from testes to urethra Urethra = tube that takes sperm out of the body Penis = for internal fertiliztion Scrotum: holds testes outside of the body cavity which lowers the temperature so sperm can survive.

Hormonal Regulation Testosterone: makes sperm develop Estrogen: thickens the uterine lining Progesterone: maintains uterine lining. Prevents ovulation. LH: causes ovulation (when ovary releases egg)

Baby Development 1. Egg + Sperm = Fertilization 2. Zygote = fertilized egg 3. Embryo = 0 to 8 weeks. Cell differentiation starts around 2 weeks. Cells start to specialize into specific body cells. 4. Fetus = 8 weeks to birth