- 1. The discovery of DNA, or deoxyribonucleic acid, is one of the most significant milestones in the field of biology, revolutionizing our understanding of genetics and heredity. This intricate molecule, which carries the genetic blueprint for all living organisms, was first identified in the 1860s by Swiss chemist Friedrich Miescher, who discovered a substance he called 'nuclein' in the nuclei of white blood cells. However, it wasn't until the early 20th century that scientists began to appreciate DNA's role in heredity. In the 1950s, James Watson and Francis Crick, building upon the foundational work of Rosalind Franklin and Maurice Wilkins, famously elucidated the double-helix structure of DNA. This pivotal model revealed how genetic information is stored and replicated, suggesting a mechanism for inheritance that could explain the transmission of traits across generations. The implications of this discovery extended far beyond biology, opening the door to advances in medicine, forensics, and biotechnology, fundamentally altering our comprehension of life itself. Today, the exploration of DNA has led to remarkable breakthroughs, including the Human Genome Project, which mapped the entire human genetic code, and CRISPR technology, which allows for precise editing of genes. The journey of DNA discovery underscores the profoundly interconnected nature of life, as it serves as the quintessential instruction manual for every organism on Earth.
Who discovered the structure of DNA?
A) Gregor Mendel
B) Charles Darwin
C) Rosalind Franklin
D) James Watson and Francis Crick
- 2. In which year was the structure of DNA discovered?
A) 1945
B) 1953
C) 1972
D) 1960
- 3. What is the full form of DNA?
A) Deoxyribonucleotide Acid
B) Double Nucleic Acid
C) Deoxyribonucleic Acid
D) Dinucleic Acid
- 4. The shape of the DNA molecule is most commonly described as?
A) Triple Strand
B) Spiral
C) Double Helix
D) Linear
- 5. Which base pairs with Adenine in a DNA molecule?
A) Cytosine
B) Thymine
C) Guanine
D) Uracil
- 6. DNA is located in which part of a eukaryotic cell?
A) Nucleus
B) Cytoplasm
C) Mitochondria
D) Endoplasmic Reticulum
- 7. Which technique was crucial in determining the structure of DNA?
A) Chromatography
B) X-ray crystallography
C) Microscopy
D) Electrophoresis
- 8. Which of the following is a purine base in DNA?
A) Cytosine
B) Guanine
C) Thymine
D) Uracil
- 9. Which nitrogenous base replaces thymine in RNA?
A) Guanine
B) Cytosine
C) Uracil
D) Adenine
- 10. What is the primary function of DNA?
A) To store and transmit genetic information
B) To regulate cellular processes
C) To synthesize proteins
D) To provide energy to cells
- 11. How many hydrogen bonds are there between Adenine and Thymine in a DNA molecule?
A) Four
B) Three
C) Two
D) One
- 12. What is the term for the process of making an RNA copy of a gene sequence?
A) Translation
B) Transcription
C) Mutation
D) Replication
- 13. What is the enzyme responsible for adding telomeric repeats to the ends of chromosomes?
A) DNA ligase
B) Telomerase
C) DNA polymerase
D) Helicase
- 14. Which of the following diseases is associated with a mutation in the DNA repair gene BRCA1?
A) Breast cancer
B) Sickle cell anemia
C) Huntington's disease
D) Cystic fibrosis
- 15. What is the term for a change in the DNA sequence that leads to a different protein being produced?
A) Translocation
B) Deletion
C) Mutation
D) Insertion
- 16. What is the term for the process of cutting DNA into smaller fragments using restriction enzymes?
A) Polymerase chain reaction
B) Restriction digestion
C) Gel electrophoresis
D) DNA ligation
- 17. Who helped Watson and Crick with X-ray diffraction data of DNA?
A) Marie Curie
B) Rosalind Franklin
C) Gregor Mendel
D) Charles Darwin
- 18. What holds the two strands of DNA together?
A) Hydrogen Bonds
B) Van der Waals Forces
C) Covalent Bonds
D) Ionic Bonds
- 19. What is the process by which DNA makes an exact copy of itself?
A) Transcription
B) Translation
C) DNA Replication
D) Mutation
- 20. What enzyme is responsible for unwinding the DNA double helix during replication?
A) Helicase
B) Ligase
C) Primase
D) Polymerase
- 21. In a DNA molecule, which nitrogenous base pairs with guanine?
A) Thymine
B) Adenine
C) Uracil
D) Cytosine
- 22. Which technique is used to amplify a specific segment of DNA?
A) DNA Sequencing
B) Southern Blotting
C) PCR (Polymerase Chain Reaction)
D) Gel Electrophoresis
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