Chapter 10: Genetic Material and Information Flow

Flashcards based on Chapter 10 lecture notes, covering genetic material, DNA replication, and information flow.

Describe Griffith's 1928 experiment.

Mixed nonpathogenic bacteria with killed pathogenic bacteria; nonpathogenic bacteria became pathogenic and passed the trait to future generations.

What was the outcome of the Hershey and Chase "blender" experiments?

Radioactive phage DNA, not protein, was found in bacteria.

What are nucleic acids?

Polynucleotides made of long chains of nucleotide monomers.

What are the single-ring pyrimidines?

Thymine (T) and Cytosine (C).

What are the double-ring purines?

Adenine (A) and Guanine (G).

What nitrogenous bases are found in DNA?

A, C, G, T.

What nitrogenous bases are found in RNA?

A, G, C, U.

What sugar is found in DNA?

Deoxyribose.

What sugar is found in RNA?

Ribose.

Who determined the three-dimensional structure of DNA?

James Watson and Francis Crick, based on X-ray crystallography by Rosalind Franklin.

What is the structure of DNA?

Two polynucleotide strands wrapped around each other.

Which bases pair together in DNA?

Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C).

What does it mean for DNA replication to be semiconservative?

Each new double helix consists of one old and one new strand.

What are origins of replication?

Specific sites on the double helix where DNA replication begins.

What is the action of the enzyme DNA polymerase?

Adds nucleotides at only the 3' end.

What is the action of the enzyme DNA ligase?

Connects the series of short pieces synthesized on one daughter strand.

What are the two main stages in which the DNA genotype is converted into a protein phenotype?

Transcription and translation.

What is a gene?

A linear sequence of many nucleotides that specifies a particular polypeptide.

What is the restated Beadle-Tatum hypothesis?

One gene-one polypeptide.

What is a triplet code?

Three-letter words (codons).

What does the genetic code specify?

Specifies the correspondence between RNA codons and amino acids in proteins.

What is the RNA that encodes an amino acid sequence and where does it occur?

mRNA; occurs in eukaryotes, RNA transcribed in the nucleus is processed before moving to the cytoplasm for translation

What are introns?

Noncoding segments that are cut out of the RNA sequence.

What are exons?

Joined to form a continuous coding sequence after introns are removed.

What is the function of transfer RNA (tRNA)?

Matches the right amino acid to the correct codon during translation.

What is transcription?

The synthesis of RNA from a DNA template.

What is translation?

The synthesis of a polypeptide from an RNA template.

What is a codon?

A three-nucleotide sequence in mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code.

What is an anticodon?

A nucleotide triplet in tRNA that base-pairs with a specific mRNA codon.

What is the role of ribosomal RNA (rRNA)?

Combines with proteins to form ribosomes, the structures that coordinate protein synthesis.

What is RNA splicing?

The process by which introns are removed from RNA transcripts and the remaining exons are joined together.

What is a promoter?

A specific nucleotide sequence in DNA that binds RNA polymerase and indicates where to start transcribing RNA.

What is a terminator?

A sequence of nucleotides in DNA that signals the end of transcription.

What are transcription factors?

Proteins that bind to DNA and regulate the transcription of genes.

What is a mutation?

A change in the nucleotide sequence of an organism's DNA.

What is a point mutation?

A mutation in which only one nucleotide base is changed.

What is a frameshift mutation?

A mutation occurring when the number of nucleotides inserted or deleted is not a multiple of three, resulting in the improper grouping of the subsequent nucleotides into codons.

What are mutagens?

Chemical or physical agents that interact with DNA to cause mutations.

What is a