OVERVIEW

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OVERVIEW

• Reproduction is the creation of new individuals
  from existing ones
• A population can exceed its finite life spans by
  reproduction
• Adaptations of animal form and function will
  contribute to their reproductive success

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46.1 Both Asexual and Sexual Reproduction Occur
in the Animal Kingdom

• 2 Modes of Animal Reproduction
• Asexual genes of new individuals come directly
  from one parent
• -relies on mitotic cell division
• Sexual new individuals created by the fusion of
  gametes to form zygotes
• - Increases genetic variability of offspring
• - Higher chance of reproductive success

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Asexual Reproduction of Sea Anemone
Earthworms Mating Sexually
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Mechanisms of Asexual Reproduction

• Fission Parent separates into two or more
  individuals of equal size
• Budding New individuals arise from outgrowths of
  existing ones
• Fragmentation Body breaks down into multiple
  pieces-some or all of these pieces develop into
  adults
• - it requires regeneration of the lost body
  parts

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Hydra Budding

• Video

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Fission in Amoeba
Yeast Cells Budding
Starfish using fragmentation
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Reproductive Cycles and Patterns

• Reproductive cycles are controlled by hormonal
  and environmental cues
• Parthenogenesis process in which egg develops
  without fertilization

Temperature
Rainfall
Lunar Cycles
Parthenogenesis in Daphnia Eggs
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Cont..

• Hermaphroditism each individual has male and
  female reproductive systems
• - some hermaphrodites self-fertilize
• Sequential hermaphroditism individual reverses
  its sex during its lifetime

Lizard hermaphrodites
Sex reversal in bluehead wrasse
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46.2 Fertilization Depends on Mechanisms that
help sperm meet eggs of same species

• 2 types of fertilization
• -External eggs shed by female are fertilized
  by sperm in external environment

-Internal egg and sperm unite in female body
Inside female body
External Fertilization frog

• Fertilization requires environmental cues

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Ensuring the Survival of Offspring

• Internal fertilization produces less zygotes
  than external
• - but survival rate higher for internal
  fertilization
• Parental care and protection of embryos results
  in few offspring by internal fertilization

Male giant water bug carrying eggs
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Gamete Production and Delivery

• Reproductive systems produce gametes and make
  them available to gametes of the opposite sex.
• Simplest Reproductive
• systems do not have gonads
• (gamete producing organs)
• Complex systems- accessory tubes
• and glands to protect/nourish gametes

Complex flatworm reproductive system
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46.3 Reproductive Organs Produce and Transport
Gametes focus on humansFemale Reproductive
Anatomy

• External human female has vulva,
• labia minora, labia majora, and clitoris
• Internal Vagina connected to uterus, which
  connects to two oviducts 2 ovaries (female
  gonads) have follicles containing egg cells
• Mammary glands present in male and
• female but only function in female

Female Reproductive System
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Male Reproductive System

• External structures scrotum and penis
• - testes (male gonads), are in cool environments
  in scrotum
• - testes have hormone producing cells and
  seminiferous tubules leading to tip of
  penis(epididymis, vas deferens, ejac. duct,
  urethra)

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Male Reproductive System
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Human Sexual Response

• 2 physiological reactions in both sexes
  vascongestion-filling of tissue with blood
• myotonia- increased muscle tension
• 4 phases of response
• -excitement
• -plateau
• -orgasm
• -resolution

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46.4 In Humans and other mammals, a complex
interplay of hormones regulates gametogenesis

• Oogenesis- female form of gametogenesis
  (production of gametes)
• Spermatogenesis- male form
• Meiosis is essential to oogenesis and
  spermatogenesis
• Differences
• - oogenesis cytokinesis is unequal-produces
  large ovum spermatogenesis starting cells
  become 4 sperms
• - oogenesis cyclic spermatogenesis
  constant/continual

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The Reproductive Cycles of Females

• Menstrual(Uterine) cycle
• proliferative and secretory phase
• - caused by ovarian cycle
• Female reproductive cycle is one integrated cycle
  
• Reproductive cycle dependent on secretion of
  GnRH, FSH, and LH

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Hormonal Control of Male Reproductive System

• Androgens (steroid hormones) from testes cause
  primary and secondary sex characteristics in
  males
• Androgen secretion and production controlled by
  hypothalamic and pituitary hormones

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46.5In humans and other placental mammals, an
embryo grows into a newborn in the mothers uterus

• Pregnancy (Gestation) carrying one or more
  embryos in the uterus
• Human pregnancy 38 weeks
• Pregnancy time, in other species, correlates with
  body size and maturity of young at birth

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Conception, Embryonic Development and Birth

• After meiosis and fertilization of egg, zygote
  becomes blastocyst
• Human pregnancy 3 trimeters
• - Baby develops with time
• - Urine contractions (parturition) causes birth
• 3 stages of birth dilation of cervix,
  expulsion, delivery of placenta

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Human Fetal Development Timeline
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Three stages of Labor
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Mothers Immune Tolerance of Embryo and Fetus

• Half embryo genes are from father foreign to
  mothers body
• Trophoblast and placenta protect embryo from
  rejection in mothers body
• - release signal molecules
• - break down tryptophan
• - induce death activator protein (FasL)

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Contraception and Abortion

• Contraception prevention of
• pregnancy
• Methods of contraception
• prevent
• -release of mature gametes
• -fertilization
• -implantation

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Modern Reproductive Technology

• Helps
• Detect any problems with developing embryo before
  birth
• People have children through in vitro
  fertilization oocytes mixed with sperms and
  incubated

Ultra Sound
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Works Cited

• "Female Infertility." Mayo Clinic. Mayo
  Foundation for Medical Education and Research.
  Web. 23 Apr. 2012. lthttp//www.mayoclinic.com/heal
  th/medical/IM01237gt.
• "Human Development." ROHAN Academic Computing.
  2007. Web. 25 Apr. 2012. lthttp//www-rohan.sdsu.ed
  u/dept/phil/fetal.htmgt.
• "Science Clarified." Birth. 2006. Web. 24 Apr.
  2012. lthttp//www.scienceclarified.com/Bi-Ca/Birth
  .htmlgt.