Processes: 46

  1. Asexual Reproduction
    • propagation of a new offspring by mitosis; one parent (monotonous reproduction Result: produces a genetically identical copy of itself, a clone; no genetic variation
    • includes fragmentation and regeneration, gemmules, parthenogenesis, fission, budding
  2. Advantages of Asexual Reproduction
    • Advantages: 
    • not finding mate; if species is scarce, they don't worry
    • more offspring at a faster rate
    • if the gene pool is favorable, it passes on, assuring persistence
    • good for stable environmental due to perpetuation of successful genotypes
  3. Disadvantages of asexual reproduction
    If there is a bad gene, it is transferredlack of diversityunfavorable genes perpetuate (deleterious)
  4. budding
    • budding: outgrowths of existing individuals; a group of cells grow on the body and, through mitosis, grows to become a new individual, which then detaches
    • ex: invertebrates
  5. gemmules
    specialized diploid cells are partitioned (set aside) somewhere in the parent--> released into the environment--> divide mitotically to form a new individual
  6. fragmentation
    • breaking into pieces, where each piece regenerates its missing part by regeneration
    • Example: earthworm
  7. parthenogenesis
    • a new haploid individual forms from an unfertilized eggIndividuals are sterile; some remain haploid; others turn diploid
    • Example: bees [worker]
    • asexual reproduction in which an egg develops without being fertilized, such as in bees, wasps, and ants
    • 1. Progeny either haploid or diploid
    • If haploid: offspring develop into adults that produce eggs and sperm without meiosis
  8. sexual reproduction
    • two parents each produce haploid gametes, fuse in fertilization, and form a diploid zygote
    • - creation of an offspring by fusion of a male gamete (sperm) and female gamete (egg) to form a zygote
  9. Disadvantages of Sexual Reproduction
    • Finding a mate
    • takes a longer time
  10. sexual reproduction advantages
    • genetic variation via recombination and independent assortment
    • - every offspring can be genetically differetn from every other offspring
    • - recombination does a good job hiding deleterious genes (recessive genes)
    • Changing environments are accommodated through adaptations
    • - shuffling of genes may rid population of harmful genes
  11. gametogenesis
    • process by which gametes are produced
    • males: spermatogenesis (formation and development of sperm) and spermiogenesis (anatomical maturity of hte sperm cell); continuous and prolific in adult males
    • females: oogenesis, the development of mature oocytes, prolonged
  12. spermatogenesis
    • the continuous and prolific production of mature sperm cells in the testes
    • nothing happens in testes until puberty; sperm not produced prior to puberty.
    • From puberty on, spermatogenesis and spermiogenesis are continuous until the end of sexual life.
    • constantly making sperm with no set end date
  13. spermiogenesis
    maturation; at the end of meiosis II, four early spermatids are the product. They are haploid and do not resemble sperm cells at all. Spermiogenesis changes them anatomically to resemble sperm
  14. oogenesis
    • egg undergoes meiosis, which is formation, at the same time she's maturing (called oogenesis)-
    • formation and maturing are happening simultaneously
    • begins in the female embryo with the production of oogonia from primordial germ cells
    • end result is one large fertilized egg
  15. menstrual cycle
    • in humans and certain other primates, a type of reproductive cycle in which the nonpregnant endometrium is shed through the cervix into the vagina
    • averages 28 days 
    • 1.      Occurs in uterus and begins with menses, which is bleeding and which is sloughing off of most of endometrium that was made the month before
    • a.       If there is a pregnancy, menses will not occur because in that endometrium is the fertilized egg
    •                                                                                                                                                   i.      If it sloughs off, the embryo goes with it
  16. ovarian cycle
    • 1.      Takes place in ovaries and is where the primary oocyte reinitiates meiosis I
    • a.       Complete meiosis I and begin meiosis II as the secondary oocyte, which will be released from the ovary in a process called ovulation
    •                                                                                                                                                   i.      It now can be fertilized
    • 2.      Objective: to get the primary oocyte to mature sufficiently that it can be ovulated, released from the ovary and into the fallopian tube

    the cyclic recurrence of the follicular phase, ovulation, and the luteal phase in the mammalian ovary, regulated by hormones
  17. estrous cycle
    • a reproductive cycle characteristic of female mammals except humans and other primates, in which the nonpregnant endometrium is reabsorbed rather than shed, and sexual response occurs only during mid-cycle at estrus 
    • animals experience "heat"
Card Set
Processes: 46
Chapter 46