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Sci 9 – Tennant
4.1 – DNA & Chromosomes
Text Assignment
Read p.125.
1. How do some cells end up as retina cells in your eye, and other cells end up as toenail cells in your foot?
Read the caption for the picture on p.125.
2. From the caption, give the example of where nuclei actually instructed their cells to die.
Read p.126, top.
3. What does DNA “carry”? (see the title for this section)
4. Where in the cell is DNA located?
5. What does DNA stand for?
6. What does DNA look like?
7. What 6 components make up a DNA molecule?
Read p.126, bottom.
8. What does the DNA “message” refer to?
9. What 2 rules are followed in how the nitrogen bases pair up?
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
10. How many base pairs long might a single human DNA molecule be?
Read p.127, bottom.
11. What is chromatin?
12. How much DNA is in each strand of chromatin?
Read p.128, top.
13. Review from grade 8 Quiz! What is a eukaryotic cell? (Circle one)
a. A cell whose individual organelles are separated from the cytoplasm by membranes
b. A cell whose individual organelles are not separated from the cytoplasm by membranes
14. What happens when a eukaryotic cell gets ready to divide into two?
15. What is a chromosome?
16. Review: A chromosome is made of c____________________________, which is made of ___ ___ ___ and
p______________________.
Read p.128, middle.
17. Chromosomes are located in the ________________________ and are found in ___________________.
18. Humans have _________ chromosomes in the nucleus of almost every cell in their bodies. They in pairs, so there are
__________ pairs.
19. Every living thing has a _____________________________ number of chromosomes.
20. How many chromosomes does a fruit fly have in each of its cells? ____________
How many pairs of chromosomes does it have in each cell? ____________
Look at table 4.1, p.129.
21. List the 6 organisms in table 4.1 and how many total chromosomes that organism has in each cell nucleus in its
body.
ORGANISM
TOTAL # CHROMOSOMES IN
CELLS
Read “Did You Know?”, p.129.
22. What is a genome?
23. How many base pairs are in each cell of your body as DNA molecules?
Read p.129, middle.
24. What is a gene?
25. What does the information on genes carry the information to produce? _____________________
26. Every chromosome contains _________________________________ of genes and therefore can make
__________________________________ of different proteins.
Read p.129, bottom and p.130, top.
27. Each __________________________________________ contains the same genetic information.
28. Why would a particular cell in your body only use the genes to make some proteins, but not others?
29. Why would ALL the genetic information be inside EVERY cell, if every cell doesn’t need all of it?
30. What is an enzyme?
31. What is a hormone?
32. Summary: A g________________ carries the instructions for making a specific protein.
Read p.131, top and side bar.
33. DRAW the 9 steps of protein production. Also copy or summarize each step in words.
HOW PROTEINS ARE MADE IN CELLS:
step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Step 6:
Step 7:
Step 8:
Step 9:
34. Complete Reading Check, p.132.
1.
2.
3.
4.
5.
Read p.132, top.
35. What did scientists think before, and what do they know now?
Read p.134.
36. What is one thing you find disturbing?
37. What is one thing you think is cool?
38. Complete Checking Concepts, p.135, #1-8,10,13 (in the space below or on separate paper).