Name: _________________________________ Date: ______ Reproduction Worksheet #_____: Life’s Greatest Miracle 1. How many human babies are born each day? 365,000 2. How many cells are there in the human body? 100 trillion cells 3. What does the video say is the “fundamental urge” for all life? To reproduce 4. What is DNA “very good” at? replicating itself 5. How does the DNA of a bacterium compare to its parent’s? all ancestors have exact DNA 6. What risk is there for a species that only reproduces by cloning? everyone would have the same immune system and one parasite could wipe us all out 7. How does the DNA of sexually produced offspring compare to the DNA of the parents? it is different from their parents and everyone else's which means that there is a variety 8. How many sperm are produced by the average human male each second? 1000 9. What process is used to make sperm cells and egg cells? meiosis 10. How many chromosomes are there in a normal human body cell? 46 chromosomes 11. What happens to the genes when two chromosomes “embrace”? genes get exchanged when they embrace 12. What is the advantage of diversity within a species? the more diversity the more likely someone will survive long enough to create the next generation 13. When does a human female produce her eggs? when the female is a fetus in her mother's womb 14. How many eggs does the average human female release per month? 1 Reproduction 15. What is an egg missing that it needs to survive? DNA from sperm 16. About how many sperm are released into the vagina? 300 million 17. What danger confronts sperm in the vagina? Acidity of the vagina 18. What does the sperm need in order to be allowed through the egg’s zona? proteins from sperm must link up with proteins from zero 19. How much time passes between fertilization and the first division of the zygote? 24 hours 20. What happens if the dividing zygote accidentally separates into two? Identical twins 21. After fertilization, how long does it take for the blastocyst to arrive in the uterus? 5 days 22. What risk does the blastocyst face after it attaches to the uterus? the blastocyst would be attacked by the mother's immune system 23. What is gastrulation? the cells organize themselves into an embryo 24. What will the lower layer of cells develop into? lungs, liver, and the lining of digestive track 25. What will the middle layer of cells develop into? heart, muscles, brain, and blood 26. What will the outer layer of cells develop into? spinal cord, brain, skin, and hair 27. How long is the embryo after 4½ weeks? 1/5 of an inch 28. True or false: All cells have the same genes. true Science Movie Worksheets – http://www.NewYorkScienceTeacher.com/movies 2 Reproduction 29. What does a gene do when it has been turned on? produce proteins 30. What do the following proteins do? a. collagen: fiber that makes up much of your skin, tendons, and bones b. crystallin: helps make the lens of your eye clear c. actin and myosin: move muscle fiber d. hemoglobin: carries oxygen from lungs to the rest of the body 31. How do cells communicate with each other? Chemical messages 32. How is the Y chromosome different from the X chromosome? The Y chromosome is one-third the size of the X chromosome and contains about 55 genes while the X chromosome has about 900 genes. 33. Where specifically does the baby get its nutrients from? the mother's blood 34. Do the baby’s and mother’s blood ever mix? No 35. How old is the fetus when it gains the ability to hear sound? 5 months 36. What is the main job of the fetus during the last trimester? To grow 37. What does myolin do? wraps around the long connections of brain cells, helps nerves move faster, enhances brain power 38. Why is birth more dangerous for humans than for other animals? the human brain is bigger than the human pelvis so sometimes there's not enough room The birth of the baby will take place at 4:25. If you don’t wish to watch, now would be a good time to look away. Science Movie Worksheets – http://www.NewYorkScienceTeacher.com/movies 3
