Question: Which items make up the prokaryotic genome?
Answer:
Plasmids
Chromosomal DNA
Question: Match the nucleic acid words with its description.
Answer:
DNA - Deoxyribonucleic acid
Chromosome - Single molecule of DNA found in the nucleoid region of bacterial cells
Gene - A small region of the chromosome that has the information to make a specific protein responsible for a specific trait
Plasmids - Small circular pieces of DNA found in the cytoplasm and give the bacterial cell an advantage
Question: In prokaryotes, the chromosome is usually...
Answer: A single, circular strand of DNA
Question: In eukaryotes, the chromosome is usually...
Answer: Multiple, linear strands of DNA
Question: DNA packaging in prokaryotes vs. eukaryotes:
Answer:
Prokaryotes: Supercoiling due to gyrase
Eukaryotes: Wrapped around histones
Question: What makes up a DNA nucleotide?
Answer:
Deoxyribose
One phosphate
One of these nitrogenous bases: adenine, guanine, cytosine, thymine
Question: What are the characteristics of a DNA molecule?
Answer:
Double helical in shape
Sugar-phosphate backbone
Strands held together by hydrogen bonds
Double stranded molecule
Question: What is the product of DNA replication?
Answer: Two identical DNA molecules
Question: In bacteria, replication occurs in...
Answer: The nucleoid region
Question: Replication is called a _______ process because each new DNA molecule contains one original strand and one new strand.
Answer: Semiconservative
Question: Match the enzyme with its role in replication.
Answer:
DNA polymerase - Adds nucleotides to the RNA primer, growing the new DNA strand
Helicase - Breaks the hydrogen bonds, separating the two DNA strands
DNA ligase - Joins the fragments of DNA together to make a continuous molecule
Primase - Lays the first nucleotides to start the new DNA strand
Question: What is the basic order of DNA replication?
Answer:
The two DNA strands are separated
An RNA primer is formed
Nucleotides are added to the RNA primer
All fragments are joined to form a continuous molecule
Question: DNA polymerase works in one direction. The strand made continuously is called the _______ strand and the strand made discontinuously is called the ___________ strand.
Answer: Leading; lagging
Question: What are Okazaki fragments?
Answer: DNA fragments made discontinuously on the lagging strand that are joined together by ligase
Question: What is the complementary strand after this DNA sequence has been replicated?
Answer:
Original: C A A G T A G
Complementary: G T T C A T C
Question: Gene expression starts with DNA and makes a...
Answer: Protein
Question: The piece of DNA on the chromosome used to make a protein is called a(n)...
Answer: Gene
Question: What makes up an RNA nucleotide?
Answer:
One of these nitrogenous bases: adenine, guanine, cytosine, uracil
One phosphate
Ribose
Question: What are the characteristics of an RNA molecule?
Answer:
Sugar-phosphate backbone
Single stranded molecule
Question: Gene expression occurs in two steps:
Answer:
Transcription: DNA transfers information to mRNA
Translation: mRNA is used to make a protein
Question: In bacteria, transcription occurs in...
Answer: The nucleoid region
Question: The enzyme that uses the DNA sequence to add nucleotides to the mRNA is...
Answer: RNA polymerase
Question: What is the product of transcription?
Answer: mRNA
Example sequence:
Original DNA: C A A G T A G
Transcribed mRNA: G U U C A U C
Question: In bacteria, translation occurs in...
Answer: The cytoplasm on the ribosome
Question: RNA's role in translation is...
Answer:
mRNA: Carries the information to the ribosome
tRNA: Brings amino acids to the ribosome
rRNA: Makes up the ribosome machinery
Question: The mRNA is read in groups of three nucleotides called a(n) ________, and the tRNA binds based on a three nucleotide sequence called a(n) ________.
Answer: Codon; Anticodon
Question: If the codon on mRNA is ACU, the tRNA that binds will have the anticodon ______. This sequence will bring in 1 amino acid.
Answer: UGA
Question: What is the relationship between codon on mRNA and the amino acid added to the protein?
Answer: The genetic code
Question: What does it mean the genetic code is universal?
Answer: All life (from bacteria to humans) uses the same codon-to-amino acid relationship.
Question: In bacteria, one piece of mRNA can be used at the same time with many ribosomes. This is called a...
Answer: Polyribosomal complex
Question: Any change in the sequence or structure of DNA is called a...
Answer: Mutation
Question: Match the mutation words with their meaning.
Answer:
Proofreading - A repair mechanism during replication where DNA polymerase checks for mistakes and repairs them
Excision repair - A repair mechanism that fixes DNA damaged by mutagens
Chemical mutagens - Substances like nitrous acid, ethidium bromide, or nicotine that cause mutations
Physical mutagens - Radiation like X-rays, gamma rays, and UV light that causes mutations
Induced mutations - Changes in DNA due to exposure to physical or chemical mutagens
Question: Bacteria gain genetic diversity through mutations and other mechanisms. Match the mechanisms with their descriptions.
Answer:
Conjugation - Plasmid DNA is transferred between bacteria via a sex pilus
Transformation - A bacterium takes up DNA from a dead bacterium
Transduction - A virus introduces bacterial DNA into a bacterium
Transposon - "Jumping genes" move within the genome, causing changes in gene expression
Question: Match the scientist with their contribution in the study of DNA.
Answer:
James Watson & Francis Crick - Determined the 3D model of DNA
Rosalind Franklin - Determined DNA was a double helix via X-ray diffraction
Frederick Griffith - Discovered transformation in bacteria
Barbara McClintock - Discovered transposons