1. Reproductive systems and Animal Development

2. Asexual Reproduction Binary fission Budding, fragmentation
Sponges, cnidarians, flatworms, annelids, echinoderms
Parthenogenesis – unfertilized egg develops into a complete individual, pg731

3. Sexual reproduction
Egg of one parent is fertilized by the sperm of another.
Dioecious – 2 sexes
Monoecious – hermaphrodites, few undergo self-fertilization, most cross fertilization
Oviparous –
Ovoviviparous –
Viviparous -

4. Advantages of Asexual vs Sexual
More offspring identical to parent
Sexual
Beneficial gene combinations that arise through recombination that speed up adaptation in a changing environment
Can rid a population of harmful genes more easily.

5. Hermaphroditism – each individual has both male and female reproductive systems – donates and receives sperm
Example: earthworms, sea slugs
Internal fertilization – sperm deposited in or near female reproductive tract, fewer gametes and zygotes produced
External fertilization – females release eggs into environment, male then fertilizes them, release of gametes by environmental cues, pheremones

6. Male Reproductive System
Testes – produce sperm and sex hormones
Epididymis – maturation of sperm
Vas deferens – store sperm
Seminal vesicles – contribute most fluid to sperm
Prostate gland – contribute fluid
Urethra – conduct sperm and urine
Bulbourethral gland – little fluid to sperm
penis

7. Sperm: hundreds of millions produced each day
Spermatogenesis –production of sperm
3 parts
Head – nucleus covered by a cap (acrosome)
Middle piece – mitochondria (energy) and microtubules
Tail – microtubules
Takes 7 weeks for 1 sperm to develop
Testosterone – main male sex hormone

8. Female Reproductive System
Ovaries – produce ovum and hormones
Oviduct (fallopian tubes) – conduct egg, fertilization
Uterus – houses embryo during development
Vagina
Oogenesis – development of mature eggs
Immature eggs form in embryo, do not complete development until fertilization

9. Fertilization

10. Cellular stages of development
Cleavage – cell division without growth
Cells get smaller with each division
Morula – ball of cells (16)
Blastula
forms a hollow ball of cells, fluid filled cavity – blastocoel when sodium leaves morula

11. Tissue stages of development
Early Gastrula – cells invaginate into the blastocoel forming the blastopore (protostomes – mouth, deuterstomes – anus)
Early gastula has 2 layers of cells,
Ectoderm – outer layer
Endoderm – primitive gut
Late gastrula – mesoderm forms
Gastrulation complete

12. Embryonic Germ Layers Ectoderm – nervous system, epidermis of skin
Mesoderm – musculoskeletal system, dermis of skin, cardiovascular system, urinary system, lymphatic system, reproductive system, outer layers of respiratory and digestive systems
Endoderm – lining of digestive tract and resp. tract, glands, thyroid/parathyroid glands

15. Developmental processes
Development requires
Growth
Cellular differentiate – cells become specialized
Morphogenesis- shape and form of body