BIO 189 Final Exam Study Guide Exam
Questions and Answers A+ Grade
2026-2027 Complete Biology Final
Exam Study Guide
DNA Structure & Discovery
1. What is Erwin Chargaff's rules for base pairing?
Answer: Bases of the two DNA strands pair in a consistent way: Adenine (A) pairs with
Thymine (T) and Cytosine (C) pairs with Guanine (G).
2. If the DNA nucleotide composition Adenine is 10%, what is the amount of Guanine?
Answer: 40%
(A = 10%, T = 10%, leaving 80% for C and G → G = 40%.)
3. What did Watson and Crick develop?
Answer: The double helix model of DNA.
4. What was Rosalind Franklin's contribution to finding DNA's structure?
Answer: Used X-ray crystallography to reveal DNA's structure.
5. Explain the Hershey and Chase experiment that contributed to the discovery of DNA.
Answer: They used bacteria and viruses to demonstrate that DNA, not protein, is injected
into host cells during infection and carries genetic information.
Chromosomes & DNA Components
6. What are sister chromatids?
Answer: Two identical copies of a chromosome joined together by a centromere.
7. What is a centromere?
Answer: The constricted region where sister chromatids are attached.
, 8. What are histones?
Answer: Proteins that DNA wraps around to form chromatin.
9. What makes up nucleotides?
Answer: A nitrogenous base, pentose sugar, and one or more phosphate groups.
10. What makes DNA nucleotides different from other nucleotides?
Answer: Their nitrogenous bases: A, T, C, and G.
11. How are nucleotide bases different in DNA and RNA?
Answer:
• DNA: A, T, C, G
• RNA: A, U, C, G
12. What type of bonds hold DNA base pairs together?
Answer: Hydrogen bonds.
13. What makes up a chromosome?
Answer: DNA and proteins (histones).
14. What is the difference between autosomes and sex chromosomes?
Answer:
• Autosomes: Determine most body traits.
• Sex chromosomes: Determine biological sex.
15. The average human has how many chromosomes?
Answer: 46 chromosomes (23 pairs).
16. What is a karyotype?
Answer: An organized picture of a person's chromosomes.
17. What information can be identified from a karyotype?
Answer: Chromosome number, size, shape, sex, and chromosomal abnormalities.
DNA Replication
18.yWhatyareytheyfunctionsyofytheyfollowingyenzymesyinyDNAyreplication?yHelicase,yLigase,yPrim
ase,yDNAyPolymerase.yUsingytheseyterms,ywhatyareytheystepsyofyDNAyreplication?
Answer:
y
Questions and Answers A+ Grade
2026-2027 Complete Biology Final
Exam Study Guide
DNA Structure & Discovery
1. What is Erwin Chargaff's rules for base pairing?
Answer: Bases of the two DNA strands pair in a consistent way: Adenine (A) pairs with
Thymine (T) and Cytosine (C) pairs with Guanine (G).
2. If the DNA nucleotide composition Adenine is 10%, what is the amount of Guanine?
Answer: 40%
(A = 10%, T = 10%, leaving 80% for C and G → G = 40%.)
3. What did Watson and Crick develop?
Answer: The double helix model of DNA.
4. What was Rosalind Franklin's contribution to finding DNA's structure?
Answer: Used X-ray crystallography to reveal DNA's structure.
5. Explain the Hershey and Chase experiment that contributed to the discovery of DNA.
Answer: They used bacteria and viruses to demonstrate that DNA, not protein, is injected
into host cells during infection and carries genetic information.
Chromosomes & DNA Components
6. What are sister chromatids?
Answer: Two identical copies of a chromosome joined together by a centromere.
7. What is a centromere?
Answer: The constricted region where sister chromatids are attached.
, 8. What are histones?
Answer: Proteins that DNA wraps around to form chromatin.
9. What makes up nucleotides?
Answer: A nitrogenous base, pentose sugar, and one or more phosphate groups.
10. What makes DNA nucleotides different from other nucleotides?
Answer: Their nitrogenous bases: A, T, C, and G.
11. How are nucleotide bases different in DNA and RNA?
Answer:
• DNA: A, T, C, G
• RNA: A, U, C, G
12. What type of bonds hold DNA base pairs together?
Answer: Hydrogen bonds.
13. What makes up a chromosome?
Answer: DNA and proteins (histones).
14. What is the difference between autosomes and sex chromosomes?
Answer:
• Autosomes: Determine most body traits.
• Sex chromosomes: Determine biological sex.
15. The average human has how many chromosomes?
Answer: 46 chromosomes (23 pairs).
16. What is a karyotype?
Answer: An organized picture of a person's chromosomes.
17. What information can be identified from a karyotype?
Answer: Chromosome number, size, shape, sex, and chromosomal abnormalities.
DNA Replication
18.yWhatyareytheyfunctionsyofytheyfollowingyenzymesyinyDNAyreplication?yHelicase,yLigase,yPrim
ase,yDNAyPolymerase.yUsingytheseyterms,ywhatyareytheystepsyofyDNAyreplication?
Answer:
y
