BIOL 1108 Edition 1nd Lecture 19 Outline of Last Lecture I Learning Objectives II Blood Sugar Regulation III IV Hormones that Regulate Blood Sugar Diabetes Mellitus V Calcium Regulation VI Hormones that Regulate Calcium Outline of Current Lecture I Learning Objectives II In The News III Sexual Variation IV Asexual Mechanism V Sexual Mechanism VI Reproductive Organs Produce and Transport Gametes VII Human Reproduction VIII Sex Hormones IX Reproductive Process in Females Current Lecture I Learning Objectives 1 Be able to These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II III IV V Compare and contrast asexual and sexual reproduction adaptations in animals Compare and contrast male and female gamete production Compare and contrast male and female hormones and cycles Compare and contrast menstrual and estrous cycles Know the four stages of embryonic development common to animals In The News How might drinking diet soda raise our risk of becoming diabetic According to a Nature article diet sodas may be a cause of metabolic diseases due to changing the microbiome of the gut Scientists in Israel tested on mice to see the effects of pure sugar and artificial sugar Those fed with artificial sweeteners like sucralose formed an intolerance to glucose Sexual Variation 1 Individuals can change sex during their lifetime 2 Individuals can function as males and females 3 In a population there may only be a few reproductive individuals 4 Animals reproduce sexually and asexually Asexual Mechanism Fission parent separates into two individuals of about equal size Ex Sea anemone Budding new individual forms from outgrowths Ex Stony coral Fragmentation regeneration reform parts of the body Ex Worms sponges cnidarians Parthenogenesis unfertilized eggs are able to develop and offspring can be haploid or diploid Ex Wasps ants bees Costs and Benefits adapted to stable environments produce more offspring at a faster rate lack genetic diversity Sexual Mechanism Reproductive cycles occur when sources are available and are regulated by hormones Fertilization Methods External fertilization eggs are released into the environment to be fertilized Internal fertilization matching copulatory organs and fewer gametes placenta temporary organ Costs and Benefits more complex better adapted to variable environments because of genetic recombination higher survival rate TOPHAT QUESTION Animals using external fertilization tend to produce more eggs per reproductive cycle than those using internal fertilization The BEST potential explanation for external fertilizers producing more eggs would be C Lower survival rates of eggs VI VII Reproductive Organs Produce and Transport Gametes Gonads organs that produce gametes not all animals have them Spermathecae sperm storage sacs many insects Cloaca opening to the outside that is shared with the digestive excretory and reproductive tracts non mammalian vertebrates ex Birds and reptiles cloaca kiss extended cloaca to transport the sperm from male to female must be a choice and accepted Human Reproduction Gametogenesis production of gametes Males Sperm small and motile Spermatogenesis continuous produce millions of sperm per day o Produce 4 viable sperm cells haploid Females Eggs larger and proved a food source for the embryo Oogenesis development of mature oocytes happens in cycles o Only one viable egg out of 4 haploid cells produced o Production of eggs prior to birth TOPHAT QUESTION During meiosis cells divide and ploidy is reduced VIII Sex Hormones Hypothalamus releases Gonadotropin releasing hormones GnRH to the Anterior Pituitary which then releases Follicle Stimulating Hormone FSH Luteinizing Hormone LH o Hormones regulate gametogenesis o Target tissues gonads males testes females ovaries Male Hormones Testosterone and Inhibin o Gamete production and affects male anatomy puberty sex drive and aggression IX Female Hormones Estradiol and Progesterone o Gamete production and affects female anatomy water retention and calcium metabolism Reproductive Process in Females 1 Hypothalamus secretes GnRH which stimulates the anterior pituitary to release FSH and LH a This stimulates the follicles to grow generally one follicle grows b If estrogen levels are low then there s going to be a negative feedback to the hypothalamus i GnRH production decreases lowering the release of FSH and LH ii Leads to the shedding of uterine lining c If estrogen levels are high then there is a positive feedback to the hypothalamus i Increases in the secretion of GnRH raises the release of FSH and LH ii When the hormone levels spike ovulation is triggered iii Increased estrogen also stimulates the development of the uterine lining 2 Ovulation the release of an egg from the ovary a If the egg is fertilized then it becomes a corpus lutem i Estrogen and progesterone maintain the uterine lining for the preparation of a fetus ii Sends negative feedback signals to anterior pituitary and hypothalamus b If the egg is not fertilized then the corpus lutem breaks down i Progesterone and estrogen levels decrease ii Menstrual cycle starts over again TOPHAT QUESTION For humans sperm can survive up to 5 days in a female reproductive tract an ovulated egg can survive 24 48 hours Which day of the menstrual cycle should a couple try to conceive B day 12 Menopause o Cessation of ovulation and menstruation typically between the ages of 46 54 o The ovaries stop responding to FSH and LH estradiol production decreases Menstrual vs Estrous Cycles Common Embryonic Development Stages o Fertilization Sperm dissolves penetrates egg s protective layer to reach the egg s plasma membrane Sperm binds to egg receptors ensures fertilization by the same species Polyspermy prevention prevents abnormal chromosome numbers o Cleavage cell division o Gastrulation germ layer formation Ectoderm outer layer Endoderm digestive tract Mesoderm middle layer for organs o Organogenesis beginning of organ development