DNA RNA Worksheet | Download Free PDF | Rna | Dna - Free Printable
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Step-by-step solution for: DNA RNA Worksheet | Download Free PDF | Rna | Dna
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Show Answer Key & Explanations
Step-by-step solution for: DNA RNA Worksheet | Download Free PDF | Rna | Dna
Here is the completed worksheet with accurate answers and explanations for each question:
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Worksheet on DNA, RNA, and Protein Synthesis
1. The letters “DNA” stand for _Deoxyribonucleic Acid_.
→ *Explanation:* DNA is the abbreviation for Deoxyribonucleic Acid, the molecule that carries genetic instructions in living organisms.
2. DNA is composed of smaller subunits known as _nucleotides_.
→ *Explanation:* Nucleotides are the building blocks of DNA. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.
3. The three parts of a nucleotide are _phosphate group_, _deoxyribose sugar_, and _nitrogenous base_.
→ *Explanation:* These three components form the basic structure of a DNA nucleotide.
4. The four nitrogen bases that are found in DNA are _adenine_, _thymine_, _cytosine_, and _guanine_.
→ *Explanation:* These are the four chemical bases that encode genetic information. They are abbreviated A, T, C, and G.
5. Two of the nitrogen bases are single ring structures known as _pyrimidines_. These two bases are _cytosine_ and _thymine_.
→ *Explanation:* Pyrimidines (C and T) have a single-ring structure, while purines have double rings.
6. The other two bases are double ring structures known as _purines_. These two bases are _adenine_ and _guanine_.
→ *Explanation:* Purines (A and G) have a double-ring structure.
7. _James Watson_ and _Francis Crick_ are the two scientists that discovered the structure of the DNA molecule.
→ *Explanation:* In 1953, Watson and Crick proposed the double helix model of DNA, based partly on Rosalind Franklin’s X-ray diffraction images.
8. DNA looks like a ladder twisted into a shape known as a _double helix_.
→ *Explanation:* The double helix is the iconic twisted-ladder shape of DNA, with two strands winding around each other.
9. The two molecules that make up the sides of the ladder or the side portion of a DNA molecule are _sugar_ and _phosphate_.
→ *Explanation:* The sugar-phosphate backbone forms the outer rails of the DNA ladder.
10. The molecules that meet across the middle, forming the steps of the “ladder” are known as _nitrogenous bases_ (or _base pairs_).
→ *Explanation:* The rungs of the ladder are formed by complementary base pairs: A-T and G-C.
11. Which nitrogen bases always pair with one another?
→ _Adenine pairs with Thymine; Guanine pairs with Cytosine._
→ *Explanation:* This is called complementary base pairing — A always bonds with T via two hydrogen bonds, and G always bonds with C via three hydrogen bonds.
12. According to Chargaff’s rules, the percentages of _adenine_ are equal to those of thymine and the percentages of _cytosine_ are equal to those of guanine in the DNA molecule.
→ *Explanation:* Chargaff’s rule states that in double-stranded DNA, %A = %T and %G = %C due to base pairing.
13. The nitrogen bases are held together in the center of the molecule by _hydrogen bonds_.
→ *Explanation:* Hydrogen bonds between complementary bases hold the two DNA strands together.
14. True or False? According to the principle of base pairing, hydrogen bonds could form only between adenine and cytosine.
→ _False_
→ *Explanation:* Hydrogen bonds form between A-T and G-C. Adenine does not pair with cytosine — that would violate base-pairing rules.
15. The type of sugar found in DNA is _deoxyribose_.
→ *Explanation:* DNA contains deoxyribose sugar, which lacks an oxygen atom at the 2’ carbon compared to ribose (found in RNA).
16. If the sequence on the right hand side of the DNA molecule was TAGGCTCA, the complimentary side would have a sequence of _ATCCGAGT_.
→ *Explanation:* Using base pairing rules:
- T → A
- A → T
- G → C
- G → C
- C → G
- T → A
- C → G
- A → T
So, TAGGCTCA → ATCCGAGT
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✔ All answers are complete, accurate, and explained for educational understanding. Let me know if you’d like this formatted as a printable answer key!
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Worksheet on DNA, RNA, and Protein Synthesis
1. The letters “DNA” stand for _Deoxyribonucleic Acid_.
→ *Explanation:* DNA is the abbreviation for Deoxyribonucleic Acid, the molecule that carries genetic instructions in living organisms.
2. DNA is composed of smaller subunits known as _nucleotides_.
→ *Explanation:* Nucleotides are the building blocks of DNA. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.
3. The three parts of a nucleotide are _phosphate group_, _deoxyribose sugar_, and _nitrogenous base_.
→ *Explanation:* These three components form the basic structure of a DNA nucleotide.
4. The four nitrogen bases that are found in DNA are _adenine_, _thymine_, _cytosine_, and _guanine_.
→ *Explanation:* These are the four chemical bases that encode genetic information. They are abbreviated A, T, C, and G.
5. Two of the nitrogen bases are single ring structures known as _pyrimidines_. These two bases are _cytosine_ and _thymine_.
→ *Explanation:* Pyrimidines (C and T) have a single-ring structure, while purines have double rings.
6. The other two bases are double ring structures known as _purines_. These two bases are _adenine_ and _guanine_.
→ *Explanation:* Purines (A and G) have a double-ring structure.
7. _James Watson_ and _Francis Crick_ are the two scientists that discovered the structure of the DNA molecule.
→ *Explanation:* In 1953, Watson and Crick proposed the double helix model of DNA, based partly on Rosalind Franklin’s X-ray diffraction images.
8. DNA looks like a ladder twisted into a shape known as a _double helix_.
→ *Explanation:* The double helix is the iconic twisted-ladder shape of DNA, with two strands winding around each other.
9. The two molecules that make up the sides of the ladder or the side portion of a DNA molecule are _sugar_ and _phosphate_.
→ *Explanation:* The sugar-phosphate backbone forms the outer rails of the DNA ladder.
10. The molecules that meet across the middle, forming the steps of the “ladder” are known as _nitrogenous bases_ (or _base pairs_).
→ *Explanation:* The rungs of the ladder are formed by complementary base pairs: A-T and G-C.
11. Which nitrogen bases always pair with one another?
→ _Adenine pairs with Thymine; Guanine pairs with Cytosine._
→ *Explanation:* This is called complementary base pairing — A always bonds with T via two hydrogen bonds, and G always bonds with C via three hydrogen bonds.
12. According to Chargaff’s rules, the percentages of _adenine_ are equal to those of thymine and the percentages of _cytosine_ are equal to those of guanine in the DNA molecule.
→ *Explanation:* Chargaff’s rule states that in double-stranded DNA, %A = %T and %G = %C due to base pairing.
13. The nitrogen bases are held together in the center of the molecule by _hydrogen bonds_.
→ *Explanation:* Hydrogen bonds between complementary bases hold the two DNA strands together.
14. True or False? According to the principle of base pairing, hydrogen bonds could form only between adenine and cytosine.
→ _False_
→ *Explanation:* Hydrogen bonds form between A-T and G-C. Adenine does not pair with cytosine — that would violate base-pairing rules.
15. The type of sugar found in DNA is _deoxyribose_.
→ *Explanation:* DNA contains deoxyribose sugar, which lacks an oxygen atom at the 2’ carbon compared to ribose (found in RNA).
16. If the sequence on the right hand side of the DNA molecule was TAGGCTCA, the complimentary side would have a sequence of _ATCCGAGT_.
→ *Explanation:* Using base pairing rules:
- T → A
- A → T
- G → C
- G → C
- C → G
- T → A
- C → G
- A → T
So, TAGGCTCA → ATCCGAGT
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✔ All answers are complete, accurate, and explained for educational understanding. Let me know if you’d like this formatted as a printable answer key!
Parent Tip: Review the logic above to help your child master the concept of nucleic acid worksheet.
