anatomy test chapter 3

  1. gametes possess how many chromosomes
  2. what are gametes
    sperm and egg
  3. all chromosomes in the body have 23 pairs of chromosomes except ______
    gametes, only have 23
  4. cells that possess 23 pairs of chromosomes are called
  5. gametes are considered
  6. meiosis
    • type of sex cell
    • starts with diploid parent cell and produces haploid daughter cell
  7. difference between meiosis and mitosis
    mitosis dividing if cells resulting cells are identical

    meiosis the dividing of sex cells resulting cells are not identical
  8. crossing over
    • occurs in meiosis
    • allows an exchange in genetic material between paired chromosomes
    • results in gametes that have genes from both parents
  9. summary of meiosis
    • 1 start with one diploid cell
    • 2 at the end of meiosis I, we have 2 daughter diploid cells
    • 3 end od Meiosis II each of the above diploid cells has produced 2 haploid cell
    • (Meiosis starts with 1 Diploid Cell and produces 4 Haploid cells)
  10. when does crossing over occur
    Prophase I
  11. spermatocytes
    parent cells that produce haploid sperm through the process of meiosis
  12. spermatids
    cells that have under gone meiosis to produce haploid cells with (23 chromosomes)
  13. where does fertilization occur
    upper 1/3 of uterine tube
  14. what do you have after to sperm and egg unite/fuse
  15. what are the 3  phases of prenatal period
    • Pre-Embryonic
    • Embryonic
    • Fetal Period
  16. pre-embryonic period
    • first 2 weeks
    • single egg (zygote)
    • cleavage & compaction & morula 
    • becomes a multicellular structure (blastocyst)
    • ends when blastocyst implants into the uterine lining
  17. Embryonic Period
    • weeks 3 to 8
    • Rudimentary versions of major organ system appear
    • Referred to as a Embryo
  18. Fetal Period
    • remaining 30 weeks
    • baby grows and prepares for birth
  19. cleavage
    after the zygote is formed it goes thru a series of mitotic divisions
  20. compaction
    although the number of cells increase the total size of the organism remains constant
  21. the 16 stage cell is called
  22. what happens in the morula
    a fluid filled blastocyst will develop in the center of the morula
  23. what happens in week 2
    • embryonic membranes are formed
    • Yolk Sac
    • amnion
    • Chorion
  24. what forms the placenta
  25. yolk sac is the site of what
    early blood cell and vessel formation
  26. Amnion
    encloses the embryo in fluid filled sac that prevents desiccation
Card Set
anatomy test chapter 3
chapter 3 study guide