3.3.13.4 DNA

• DNA is a double-stranded molecule composed of nucleotides
• Match the base pairing with the number of hydrogen bonds:

  A-T ↔️ 2

  G-C ↔️ 3
• Which base pairs with Adenine (A) in DNA?

  Thymine (T)
• How many hydrogen bonds are between G-C base pairs?

  3
• Match the key component of DNA with its description:

  Two Strands ↔️ Two chains of nucleotides intertwined

  Complementary Base Pairing ↔️ A pairs with T, G pairs with C

  Sugar-Phosphate Backbone ↔️ Provides structural support and connects nucleotides
• Which enzyme unwinds the DNA double helix at replication origins?

  Helicase
• What is the role of ligase in DNA replication?

  Joins Okazaki fragments
• Transcription occurs in the nucleus of the cell.


  True
• What are the three main components of a nucleotide in DNA?

  Sugar, phosphate, base
• The deoxyribose sugar forms the sugar-phosphate backbone
• Adenine (A) pairs with Thymine (T) using 2 hydrogen bonds.
• Match the DNA component with its description:

  Two Strands ↔️ Chains of nucleotides intertwined

  Complementary Base Pairing ↔️ A pairs with T, G pairs with C

  Sugar-Phosphate Backbone ↔️ Connects nucleotides and provides support
• Steps in DNA replication

  1️⃣ Initiation: Helicase unwinds DNA at replication origins

  2️⃣ Elongation: DNA polymerase adds nucleotides to the 3' end

  3️⃣ Termination: Ligase seals gaps between Okazaki fragments
• Steps in transcription

  1️⃣ Initiation: RNA polymerase binds to the promoter

  2️⃣ Elongation: RNA polymerase synthesizes a complementary RNA strand

  3️⃣ Termination: RNA polymerase reaches a termination signal
• Steps in the process of transcription

  1️⃣ RNA polymerase binds to the promoter region on DNA

  2️⃣ RNA polymerase moves along DNA, synthesizing a complementary RNA strand

  3️⃣ RNA polymerase reaches a termination signal, releasing the RNA transcript
• Translation uses the genetic information encoded in mRNA to direct the synthesis of proteins.


  True
• Where is DNA found in a cell?

  Nucleus
• The specific sequence of nitrogenous bases in DNA defines the genetic instructions.


  True
• Which type of bond holds together the base pairs in DNA?

  Hydrogen bond
• There are two hydrogen bonds between A-T base pairs.


  True
• DNA has a double helix structure.


  True
• Steps of DNA replication

  1️⃣ Initiation

  2️⃣ Elongation

  3️⃣ Termination
• The leading strand in DNA replication is synthesized continuously.

  True
• Match the type of RNA with its function:

  mRNA ↔️ Carries genetic code to ribosomes

  tRNA ↔️ Transports amino acids to ribosomes

  rRNA ↔️ Forms part of the ribosome structure
• The sugar-phosphate backbone of DNA is formed by deoxyribose
• Hydrogen bonds provide stability to the DNA double helix structure


  True
• The sugar-phosphate backbone provides structural support to DNA


  True
• Genes in DNA control protein synthesis and cell differentiation


  True
• DNA replication is semi-conservative because each new molecule has one original strand


  True
• DNA replication is semi-conservative because each new DNA molecule consists of one original strand and one newly synthesized strand
• Translation occurs at the ribosomes
• What is the role of tRNA during translation?

  Carries specific amino acids
• What are Short Tandem Repeats (STRs) used for in DNA profiling?

  Creating unique genetic profiles
• Mutations in DNA can be classified as either point mutations or chromosomal
• Steps in the process of DNA profiling

  1️⃣ Sample Collection

  2️⃣ DNA Extraction

  3️⃣ STR Analysis

  4️⃣ DNA Comparison
• What does DNA stand for?

  Deoxyribonucleic Acid
• What are the three main components of a nucleotide?

  Deoxyribose sugar, phosphate group, nitrogenous base
• Adenine (A) always pairs with Thymine
• Base pairing in DNA is fundamental to its structure and function
• The specific number of hydrogen bonds in DNA ensures that the strands remain tightly connected