25238054 | PDF - Free Printable
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Step-by-step solution for: 25238054 | PDF
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Show Answer Key & Explanations
Step-by-step solution for: 25238054 | PDF
Let’s go through each question one by one and solve them step by step.
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17. Label the parts of the drawing below. Include all of these terms: nucleotide, phosphate, sugar, nitrogen base, hydrogen bond, covalent bond, purine, pyrimidine, hydroxyl group, the 5’ end, the 3’ end, adenine, thymine, cytosine, and guanine.
Since we can’t see the actual drawing, I’ll explain how to label a standard DNA double helix diagram using those terms:
- Nucleotide: Each “rung” + its backbone piece is one nucleotide (made of sugar + phosphate + base).
- Phosphate: The circle or P-shaped part in the backbone.
- Sugar: The pentagon shape connected to phosphate and base.
- Nitrogen base: The shapes sticking inward — A, T, C, G.
- Hydrogen bond: Dotted lines between bases (A-T has 2, C-G has 3).
- Covalent bond: Solid lines connecting sugar-phosphate-sugar in the backbone.
- Purine: Adenine and Guanine (double-ring bases).
- Pyrimidine: Thymine and Cytosine (single-ring bases).
- Hydroxyl group: OH group on the 3’ carbon of the sugar (usually at the end of the strand).
- 5’ end: End of the strand with a free phosphate group.
- 3’ end: End of the strand with a free hydroxyl group.
- Adenine (A): Pairs with Thymine.
- Thymine (T): Pairs with Adenine.
- Cytosine (C): Pairs with Guanine.
- Guanine (G): Pairs with Cytosine.
👉 *In your drawing, find the backbone (sugar-phosphate), then the bases inside. Match each term to its location.*
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18. The process in which DNA builds an exact duplicate of itself is known as _______________.
This is called DNA replication.
✔ Final Answer for #18: DNA replication
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19. What is the primary function of DNA?
DNA holds the instructions for building and running an organism — it stores genetic information that tells cells how to make proteins and control traits.
✔ Final Answer for #19: To store and transmit genetic information
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20. Why is it so important that DNA molecules be able to make copies of itself?
Because when a cell divides, each new cell needs a full set of DNA. If DNA couldn’t copy itself, cells couldn’t divide properly, and organisms couldn’t grow, repair, or reproduce.
✔ Final Answer for #20: So that each new cell gets a complete set of genetic instructions during cell division
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21. During replication, the two nucleotide chains ____________, and each chain serves as a ____________ for a new nucleotide chain. The sites where DNA replication and separation occur are called ____________.
- First blank: separate (or unwind)
- Second blank: template
- Third blank: replication forks
✔ Final Answer for #21: separate; template; replication forks
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22. During replication, enzymes called ____________ untwist the double helix, separating the two parental strands. The point at which the two chains separate is known as the ____________.
- First blank: helicases
- Second blank: replication fork
✔ Final Answer for #22: helicases; replication fork
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23. Enzymes called ____________ move along the separated strands assembling the new chains of DNA.
These are DNA polymerases — they add new nucleotides to build the new strand.
✔ Final Answer for #23: DNA polymerases
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24. True or False? The replication of DNA begins at one end of the molecule and proceeds to the other end.
False. In most cases (especially in circular bacterial DNA or eukaryotic chromosomes), replication starts at multiple points called origins of replication, not just one end.
✔ Final Answer for #24: False
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25. True or False? DNA replication occurs simultaneously at many sites along the molecule speeding up the process of replication.
True. This is why large DNA molecules can replicate quickly — multiple replication forks work at once.
✔ Final Answer for #25: True
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26. When replication is complete, two ____________ copies of the DNA molecule have been produced and the cell is ready to begin ____________.
- First blank: identical
- Second blank: cell division (or mitosis)
✔ Final Answer for #26: identical; cell division
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27. True or False? Each DNA molecule resulting from replication has one original strand and one new strand.
True. This is called semi-conservative replication — each new DNA molecule keeps one old strand and makes one new strand.
✔ Final Answer for #27: True
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## Final Answers:
17. *(Labeling task — refer to explanation above)*
18. DNA replication
19. To store and transmit genetic information
20. So that each new cell gets a complete set of genetic instructions during cell division
21. separate; template; replication forks
22. helicases; replication fork
23. DNA polymerases
24. False
25. True
26. identical; cell division
27. True
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17. Label the parts of the drawing below. Include all of these terms: nucleotide, phosphate, sugar, nitrogen base, hydrogen bond, covalent bond, purine, pyrimidine, hydroxyl group, the 5’ end, the 3’ end, adenine, thymine, cytosine, and guanine.
Since we can’t see the actual drawing, I’ll explain how to label a standard DNA double helix diagram using those terms:
- Nucleotide: Each “rung” + its backbone piece is one nucleotide (made of sugar + phosphate + base).
- Phosphate: The circle or P-shaped part in the backbone.
- Sugar: The pentagon shape connected to phosphate and base.
- Nitrogen base: The shapes sticking inward — A, T, C, G.
- Hydrogen bond: Dotted lines between bases (A-T has 2, C-G has 3).
- Covalent bond: Solid lines connecting sugar-phosphate-sugar in the backbone.
- Purine: Adenine and Guanine (double-ring bases).
- Pyrimidine: Thymine and Cytosine (single-ring bases).
- Hydroxyl group: OH group on the 3’ carbon of the sugar (usually at the end of the strand).
- 5’ end: End of the strand with a free phosphate group.
- 3’ end: End of the strand with a free hydroxyl group.
- Adenine (A): Pairs with Thymine.
- Thymine (T): Pairs with Adenine.
- Cytosine (C): Pairs with Guanine.
- Guanine (G): Pairs with Cytosine.
👉 *In your drawing, find the backbone (sugar-phosphate), then the bases inside. Match each term to its location.*
---
18. The process in which DNA builds an exact duplicate of itself is known as _______________.
This is called DNA replication.
✔ Final Answer for #18: DNA replication
---
19. What is the primary function of DNA?
DNA holds the instructions for building and running an organism — it stores genetic information that tells cells how to make proteins and control traits.
✔ Final Answer for #19: To store and transmit genetic information
---
20. Why is it so important that DNA molecules be able to make copies of itself?
Because when a cell divides, each new cell needs a full set of DNA. If DNA couldn’t copy itself, cells couldn’t divide properly, and organisms couldn’t grow, repair, or reproduce.
✔ Final Answer for #20: So that each new cell gets a complete set of genetic instructions during cell division
---
21. During replication, the two nucleotide chains ____________, and each chain serves as a ____________ for a new nucleotide chain. The sites where DNA replication and separation occur are called ____________.
- First blank: separate (or unwind)
- Second blank: template
- Third blank: replication forks
✔ Final Answer for #21: separate; template; replication forks
---
22. During replication, enzymes called ____________ untwist the double helix, separating the two parental strands. The point at which the two chains separate is known as the ____________.
- First blank: helicases
- Second blank: replication fork
✔ Final Answer for #22: helicases; replication fork
---
23. Enzymes called ____________ move along the separated strands assembling the new chains of DNA.
These are DNA polymerases — they add new nucleotides to build the new strand.
✔ Final Answer for #23: DNA polymerases
---
24. True or False? The replication of DNA begins at one end of the molecule and proceeds to the other end.
False. In most cases (especially in circular bacterial DNA or eukaryotic chromosomes), replication starts at multiple points called origins of replication, not just one end.
✔ Final Answer for #24: False
---
25. True or False? DNA replication occurs simultaneously at many sites along the molecule speeding up the process of replication.
True. This is why large DNA molecules can replicate quickly — multiple replication forks work at once.
✔ Final Answer for #25: True
---
26. When replication is complete, two ____________ copies of the DNA molecule have been produced and the cell is ready to begin ____________.
- First blank: identical
- Second blank: cell division (or mitosis)
✔ Final Answer for #26: identical; cell division
---
27. True or False? Each DNA molecule resulting from replication has one original strand and one new strand.
True. This is called semi-conservative replication — each new DNA molecule keeps one old strand and makes one new strand.
✔ Final Answer for #27: True
---
## Final Answers:
17. *(Labeling task — refer to explanation above)*
18. DNA replication
19. To store and transmit genetic information
20. So that each new cell gets a complete set of genetic instructions during cell division
21. separate; template; replication forks
22. helicases; replication fork
23. DNA polymerases
24. False
25. True
26. identical; cell division
27. True
Parent Tip: Review the logic above to help your child master the concept of dna to rna to protein worksheet.
