MICRO 9

Flashcard 1

Question: Which items make up the prokaryotic genome?
Answer:

  • Plasmids

  • Chromosomal DNA

Flashcard 2

Question: Match the nucleic acid words with its description.
Answer:

  1. DNA - Deoxyribonucleic acid

  2. Chromosome - Single molecule of DNA found in the nucleoid region of bacterial cells

  3. Gene - A small region of the chromosome that has the information to make a specific protein responsible for a specific trait

  4. Plasmids - Small circular pieces of DNA found in the cytoplasm and give the bacterial cell an advantage

Flashcard 3

Question: In prokaryotes, the chromosome is usually...
Answer: A single, circular strand of DNA

Flashcard 4

Question: In eukaryotes, the chromosome is usually...
Answer: Multiple, linear strands of DNA

Flashcard 5

Question: DNA packaging in prokaryotes vs. eukaryotes:
Answer:

  • Prokaryotes: Supercoiling due to gyrase

  • Eukaryotes: Wrapped around histones

Flashcard 6

Question: What makes up a DNA nucleotide?
Answer:

  • Deoxyribose

  • One phosphate

  • One of these nitrogenous bases: adenine, guanine, cytosine, thymine

Flashcard 7

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

Flashcard 8

Question: What is the product of DNA replication?
Answer: Two identical DNA molecules

Flashcard 9

Question: In bacteria, replication occurs in...
Answer: The nucleoid region

Flashcard 10

Question: Replication is called a _______ process because each new DNA molecule contains one original strand and one new strand.
Answer: Semiconservative

Flashcard 11

Question: Match the enzyme with its role in replication.
Answer:

  1. DNA polymerase - Adds nucleotides to the RNA primer, growing the new DNA strand

  2. Helicase - Breaks the hydrogen bonds, separating the two DNA strands

  3. DNA ligase - Joins the fragments of DNA together to make a continuous molecule

  4. Primase - Lays the first nucleotides to start the new DNA strand

Flashcard 12

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

Flashcard 13

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

Flashcard 14

Question: What are Okazaki fragments?
Answer: DNA fragments made discontinuously on the lagging strand that are joined together by ligase

Flashcard 15

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

Flashcard 16

Question: Gene expression starts with DNA and makes a...
Answer: Protein

Flashcard 17

Question: The piece of DNA on the chromosome used to make a protein is called a(n)...
Answer: Gene

Flashcard 18

Question: What makes up an RNA nucleotide?
Answer:

  • One of these nitrogenous bases: adenine, guanine, cytosine, uracil

  • One phosphate

  • Ribose

Flashcard 19

Question: What are the characteristics of an RNA molecule?
Answer:

  • Sugar-phosphate backbone

  • Single stranded molecule

Flashcard 20

Question: Gene expression occurs in two steps:
Answer:

  • Transcription: DNA transfers information to mRNA

  • Translation: mRNA is used to make a protein

Flashcard 21

Question: In bacteria, transcription occurs in...
Answer: The nucleoid region

Flashcard 22

Question: The enzyme that uses the DNA sequence to add nucleotides to the mRNA is...
Answer: RNA polymerase

Flashcard 23

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

Flashcard 24

Question: In bacteria, translation occurs in...
Answer: The cytoplasm on the ribosome

Flashcard 25

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

Flashcard 26

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

Flashcard 27

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

Flashcard 28

Question: What is the relationship between codon on mRNA and the amino acid added to the protein?
Answer: The genetic code

Flashcard 29

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.

Flashcard 30

Question: In bacteria, one piece of mRNA can be used at the same time with many ribosomes. This is called a...
Answer: Polyribosomal complex

Flashcard 31

Question: Any change in the sequence or structure of DNA is called a...
Answer: Mutation

Flashcard 32

Question: Match the mutation words with their meaning.
Answer:

  1. Proofreading - A repair mechanism during replication where DNA polymerase checks for mistakes and repairs them

  2. Excision repair - A repair mechanism that fixes DNA damaged by mutagens

  3. Chemical mutagens - Substances like nitrous acid, ethidium bromide, or nicotine that cause mutations

  4. Physical mutagens - Radiation like X-rays, gamma rays, and UV light that causes mutations

  5. Induced mutations - Changes in DNA due to exposure to physical or chemical mutagens

Flashcard 33

Question: Bacteria gain genetic diversity through mutations and other mechanisms. Match the mechanisms with their descriptions.
Answer:

  1. Conjugation - Plasmid DNA is transferred between bacteria via a sex pilus

  2. Transformation - A bacterium takes up DNA from a dead bacterium

  3. Transduction - A virus introduces bacterial DNA into a bacterium

  4. Transposon - "Jumping genes" move within the genome, causing changes in gene expression

Flashcard 34

Question: Match the scientist with their contribution in the study of DNA.
Answer:

  1. James Watson & Francis Crick - Determined the 3D model of DNA

  2. Rosalind Franklin - Determined DNA was a double helix via X-ray diffraction

  3. Frederick Griffith - Discovered transformation in bacteria

  4. Barbara McClintock - Discovered transposons