ap bio unit 6 flash cards

What are the two main types of nucleic acids?

DNA and RNA.

What is a nucleotide composed of?

A nucleotide is composed of a phosphate group, a nitrogenous base, and a five-carbon sugar.

Which nitrogenous bases are classified as purines?

Adenine (A) and Guanine (G).

What are the complementary base pairs in DNA?

A pairs with T and G pairs with C.

What is the structure of DNA described as?

A double helix.

What model describes how DNA is replicated?

The semiconservative model.

What role does helicase play in DNA replication?

Helicase unwinds the DNA strands.

What are Okazaki fragments?

Short segments synthesized on the lagging strand during DNA replication.

What is the function of DNA ligase?

DNA ligase joins the sugar-phosphate backbones of Okazaki fragments into a continuous DNA strand.

What is the primary role of RNA polymerase in transcription?

To bind to the promoter region and synthesize RNA.

What is a codon?

A three-nucleotide sequence on mRNA that specifies an amino acid.

What is an operon?

A segment of DNA that includes a series of structural genes and control elements regulating their transcription.

What occurs during feedback inhibition in gene regulation?

A surplus of end product inhibits further production by preventing transcription.

What is the effect of DNA methylation on gene expression?

DNA methylation causes the expression of genes to stop.

What distinguishes a missense mutation from a nonsense mutation?

A missense mutation affects one amino acid, while a nonsense mutation introduces a stop codon, leading to a nonfunctional protein.

What is the role of telomerase?

Telomerase helps maintain the length of telomeres, preventing chromosome shortening.

Fill in the blank: The genetic code consists of ________ nucleotide bases.

four

Fill in the blank: The process of synthesizing RNA from a DNA template is called ________.

transcription

Fill in the blank: The sequence of three nucleotides on tRNA that matches a codon is called an ________.

anticodon

Fill in the blank: During the S phase of interphase, DNA ________ occurs.

replication

Fill in the blank: In the central dogma of molecular biology, information flows from DNA to ________ to protein.

RNA

Fill in the blank: The enzyme that adds new nucleotides during DNA replication is called ________.

DNA polymerase

Fill in the blank: ________ are segments of DNA that do not code for proteins, found between genes.

Introns

Fill in the blank: The termination of transcription occurs when RNA polymerase reaches a ________ signal.

termination

Fill in the blank: In eukaryotic cells, ________ are the structures where protein synthesis occurs.

ribosomes

Fill in the blank: The region of DNA where RNA polymerase binds to initiate transcription is called the ________ region.

promoter