Lab #3

  1. Our bodies want to make ________.
    babies
  2. Around the world, about ________ new babies get made every day.
    265,000
  3. From a _______ ____, you built a body that has 100 trillion cells.
    single cell
  4. At least some blame for the urge to reproduce can go to this...._____.
    DNA
  5. If humans were all clones, we'd have the exact same ______ ______ and one successful parasite could wipe us all out. Fortunately, there's ____.
    immune system, sex
  6. When there's sex, there's ________ and when it comes to survival of the fittest, ______ has a definite advantage.
    variety, variety
  7. The tubes in the testes can stretch out to cover ___________. What are they called?
    half a mile, semineferous tubules
  8. A man can produce ______ new sperm every second, 100 million every day, 2 trillion over a lifetime.
    1000
  9. Each sperm is carrying a unique ______ package.
    genetic
  10. How does this genetic activity happen? By a process called _______.
    myosis
  11. We have _______ genes spread out over 46 chromosomes.
    50,000
  12. The more _______, the better the odds are that someone will survive to create a new generation.
    diversity
  13. Melinda created _______________ when she was a fetus in her mother's womb.
    all of her eggs
  14. At the age of 31, she may only have a few __________ eggs left.
    thousand
  15. The egg is swept along the felopian tube by muscular contraction and the action of ______.
    cilia
  16. If the egg is not fertilized within a few _____, it will die.
    hours
  17. The sperm travel along a ___ inch tube looping into the abdomen and penis.
    15
  18. The semen is only about a teaspoon but contains ____ million sperm.
    300
  19. Even in a healthy man, ___% of sperm are less than perfect.
    60
  20. For a few days a month around ovulation, the mucus plug over the cervix becomes ______.
    watery
  21. It is estimated that ____% of all fertilized eggs fail to develop.
    50
  22. About 5 days after fertilization, the dividing cells arrive in ______, about 100 small cells trapped within the zona.
    uterus
  23. The Blastocyst burrows into the uterine lining searching for ______________.
    food and oxygen
  24. 2 weeks after conception, the blastocyst is the size of a _________.
    poppyseed
  25. Gastrulation is the process of the blastocyst changing into an _______.
    embryo
  26. 3 weeks after fertilization, the embryo is less than a ___th of an inch.
    10
  27. At 4.5 weeks the embryo is 1/5 of an inch long, has a ___, a large developing brain and eye.
    tail
  28. If all DNA in a single cell were unwound, it would be __ft long.
    6
  29. At 7 weeks old, boy and girl embryos look ________, inside and out.
    identical
  30. A gene on the Y chromosome called ____ turns on for a day or two setting off a chain of events leading to testes.
    SRY
  31. 2 months after fertilization, the embryo now called a _____, is just over an inch and less than a third of an ounce.
    fetus
  32. The Placenta's underside has 1000's of _____ which lie in pools of the mom's blood.
    villi
  33. (true/false) The mother's blood normally never mixes with the blood of the fetus.
    true
  34. The fetus's heart beasts _____ as fast as adults.
    twice
  35. Most of the bones in the fetus start as __________.
    cartilage
  36. After 5 months the fetus can ____.
    hear
  37. At week 8 the fetus is ___ inch long with fingers and toes. At 12 weeks it is 3 inches, at 16 weeks it is 5 inches.
    1
  38. During the last __________, all organs are in place and they mostly need to grow.
    trimester
  39. During the 6th month, genes order the manufacture of a fatty covering for the neurons called _______.
    myelin
  40. Human births are far more dangerous due to the brain being 3x larger than other primates and humans have a ______ pelvis for walking.
    narrow
Author
Anonymous
ID
13653
Card Set
Lab #3
Description
Life's Greatest Miracle
Updated