U6 Test - hailee

ch. 12,13,14

What are the building blocks of DNA?

Nucleotides

What sugar is found in DNA?

Deoxyribose

Name the four nitrogenous bases in DNA.

Adenine, Guanine, Cytosine, Thymine

What type of bond links nucleotides in the DNA backbone?

Phosphate bonds

Who deduced the structure of DNA in 1953?

Watson, Crick, and Franklin

What pairs with adenine in DNA?

Thymine (A-T)

What pairs with cytosine in DNA?

Guanine (G-C)

What is the term for the ends of a DNA molecule?

Telomeres

What is the process of copying DNA called?

DNA replication

Which enzyme unwinds the DNA double helix during replication?

Helicase

What is the role of DNA polymerase?

Adds nucleotides to the growing DNA strand

What are Okazaki fragments?

Pieces of DNA synthesized on the lagging strand

What enzyme links Okazaki fragments together?

DNA ligase

What is the term for the genetic material in a species?

Genome

What is euchromatin?

Loose form of DNA that is active for transcription

What is heterochromatin?

Condensed form of DNA that is generally inactive

What is the process of making RNA from DNA called?

Transcription

What replaces thymine in RNA?

Uracil

What is the function of mRNA?

Temporary RNA version of a DNA recipe sent to the ribosome

What is the role of tRNA?

Brings amino acids to the ribosomes

What are exons?

Coding regions of mRNA

What are introns?

Noncoding regions in the mRNA

What is splicing?

The process of removing introns from mRNA

What is added to the 3′ end of mRNA during processing?

Poly(A) tail

What is added to the 5′ end of mRNA during processing?

5′ GTP cap

What is the process of translating mRNA into protein called?

Translation

Where does translation occur in the cell?

On ribosomes in the cytoplasm and on the rough endoplasmic reticulum.

What is a codon?

A sequence of three nucleotides in mRNA that corresponds to a particular amino acid.

What are the two ends of tRNA responsible for?

One end carries an amino acid, and the other end, called the anticodon, pairs with the codon in mRNA.

What is wobble pairing in tRNA?

allows non-standard base pairing, such as guanine pairing with uracil.

What are the three phases of translation?

Initiation, elongation, and termination.

What initiates the translation process?

A ribosome attaches to the mRNA.

What are the three binding sites in a ribosome?

A site, P site, and E site.

What is the start codon and what amino acid does it code for?

A-U-G, which codes for methionine.

What occurs during the elongation phase of translation?

Amino acids are added to form a polypeptide.

What signifies the termination of translation?

The ribosome encounters a stop codon.

What is pre-transcriptional regulation?

Regulation of gene expression that occurs before transcription.

What role do transcription factors play?

They can encourage or inhibit the transcription of genes.

What are operons?

Clusters of genes under the control of a single promoter in bacteria.

What are the four major parts of an operon?

Structural genes, promoter genes, the operator, and the regulatory gene.

What is the function of the repressor in gene regulation?

The repressor binds to the operator to block transcription.

What is RNA interference (RNAi)?

A process where RNA molecules bind to RNA to prevent translation.

What is morphogenesis?

The process by which cells change shape and organization during development.

What are homeotic genes?

Early genes that determine the fate of cells in the embryo.

What is a mutation?

An error in the genetic code.

What are the three types of point mutations?

Nonsense mutations, missense mutations, and silent mutations.

What is a frameshift mutation?

A mutation caused by insertions or deletions that alters the reading frame of codons.

What are transposons?

Gene segments that can move within the genome and potentially disrupt gene expression.

What are the two main components of a virus?

A protein shell (capsid) and genetic material (DNA or RNA).

What is the lytic cycle in viral replication?

A cycle where the virus immediately uses the host's machinery to replicate.

What is transduction in bacteria?

The transfer of DNA between bacterial cells using a lysogenic virus.

What is recombinant DNA?

DNA generated by combining DNA from multiple sources.

What is the purpose of the Polymerase Chain Reaction (PCR)?

To create billions of identical copies of genes within hours.

What is gel electrophoresis used for?

To separate DNA fragments based on their molecular weight and charge.

What are restriction fragment length polymorphisms (RFLPs)?

Differences in DNA sequences that result in fragments of varying lengths.

What does DNA sequencing allow scientists to do?

Determine the order of nucleotides in a DNA molecule.