Biology 1 - Chp 12 - DNA & RNA Flashcards

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Questions and Answers

The process by which one strain of bacteria is apparently changed into another strain is called?

transformation

Bacteriophages are?

viruses

A nucleotide does NOT contain?

polymerase

In prokaryotes, DNA molecules are located in the?

cytoplasm Signup and view all the answers

The process of DNA?

replication Signup and view all the answers

The main enzyme involved in linking individual nucleotides into DNA molecules is?

DNA polymerase Signup and view all the answers

The process by which the genetic code of DNA is copied into a strand of RNA is called?

transcription Signup and view all the answers

In messenger RNA, each codon specifies a particular?

amino acid Signup and view all the answers

Changes in the DNA that affect genetic information are known as?

mutations Signup and view all the answers

An expressed gene is one that?

is transcribed into RNA Signup and view all the answers

What three critical gene functions had scientists identified?

Genes carry information from one generation to the next, determine heritable characteristics, and are replicated easily. Signup and view all the answers

Describe the components and structure of a DNA nucleotide.

DNA is a long molecule made up of nucleotides. Each nucleotide has three parts: 5-carbon sugar called deoxyribose, a phosphate group, and a nitrogenous base. The four nitrogenous bases are adenine and guanine, which are purines, and cytosine and thymine, which are pyrimidines. Signup and view all the answers

How did Chargaff's rules help Watson and Crick model DNA?

Adenine bonds only to thymine and cytosine bonds only to guanine. Signup and view all the answers

What is meant by the term 'base pairing'?

Hydrogen bonds form only between certain base pairs (A and T, C and G). Signup and view all the answers

How is base pairing involved in DNA replication?

Complementary strands produced are identical to the original strands. Signup and view all the answers

Describe the appearance of DNA in a typical prokaryotic cell.

It has a single, circular DNA molecule that contains nearly all of the cell's genetic information. Signup and view all the answers

Explain the process of replication.

Each new DNA molecule has one strand from the original molecule and one new strand. Signup and view all the answers

When a DNA molecule is replicated, how do the new molecules relate to the original molecule?

Both new molecules are identical to the original one. Signup and view all the answers

Describe the relationship between DNA, chromatin, histones, and nucleosomes.

Nucleosomes are made up of DNA wrapped around histones. Chromatin is long chains of nucleosomes. Signup and view all the answers

What is the difference between exons and introns?

Pre-RNA contains introns, which must be removed before RNA becomes active. The remaining RNA, exons, are the actual genetic message used to assemble proteins. Signup and view all the answers

What is a codon?

A codon consists of three nucleotides that specify a single amino acid that is to be added to a polypeptide. Signup and view all the answers

What is an anticodon?

An anticodon consists of the three bases on the tRNA molecule that are complementary to an mRNA codon. Signup and view all the answers

How does the anticodon function?

Anticodons determine which tRNA binds to the codon on mRNA, and thus which amino acid is attached to the polypeptide chain. Signup and view all the answers

If a codon on a DNA molecule for a specific amino acid is CTA, what would be the messenger RNA codon?

GAU Signup and view all the answers

What would be the transfer RNA anticodon for the codon CTA?

CUA Signup and view all the answers

Explain why controlling the proteins in an organism controls the organism's characteristics.

Proteins are responsible for catalyzing and regulating chemical reactions, as well as regulating the rate and pattern of growth. These actions help determine an organism's characteristics. Signup and view all the answers

Name two major types of mutations.

Gene and chromosomal Signup and view all the answers

What do gene mutations and chromosomal mutations have in common?

Both change the DNA sequence that affects genetic information. Signup and view all the answers

How are gene mutations and chromosomal mutations different?

Gene mutations involve a change in one or several nucleotides in a single gene, whereas chromosomal mutations involve changes in the number or structure of the whole chromosome. Signup and view all the answers

Give an example of a gene mutation.

A point mutation Signup and view all the answers

Give an example of a chromosomal mutation.

A deletion or duplication of a chromosome segment Signup and view all the answers

Describe how the TATA box helps position RNA polymerase in a eukaryotic cell.

It marks a point just before the point at which transcription begins. Signup and view all the answers

Describe the role of an operon in a prokaryotic cell.

An operon is a series of genes that code for specific products and the regulatory elements that control operator DNA segments. Signup and view all the answers

Give an example of how an operon works.

The Lac operon in E. coli Signup and view all the answers

Study Notes

Transformation and Bacteriophages

Transformation is the process where one strain of bacteria is converted into another strain.
Bacteriophages are types of viruses that infect bacteria.

Nucleotides and DNA Structure

A nucleotide does not contain polymerase.
DNA in prokaryotes is located in the cytoplasm, appearing as a single, circular molecule.

DNA Replication

DNA replication is the process of creating duplicate DNA strands.
The main enzyme that links nucleotides into DNA is DNA polymerase.
Replicated DNA molecules consist of one original and one new strand, making it a semiconservative process.

Transcription and RNA

Transcription is the process of copying the genetic code from DNA into RNA.
Each codon in messenger RNA specifies an amino acid.
An anticodon is a set of three bases on a tRNA molecule that pairs with a specific mRNA codon.

Mutations and Gene Function

Mutations are changes in DNA that affect genetic information.
An expressed gene is actively transcribed into RNA, playing a role in traits and characteristics.
Two major types of mutations are gene mutations (altering one or several nucleotides) and chromosomal mutations (affecting chromosome number or structure).

Components of a DNA Nucleotide

A DNA nucleotide comprises a deoxyribose sugar, a phosphate group, and a nitrogenous base (adenine, thymine, guanine, cytosine).
Chargaff's rules dictate that adenine always pairs with thymine, and cytosine pairs with guanine.

Gene Structure and Function

Pre-RNA contains introns (non-coding sequences) that are removed during RNA processing, leaving exons (coding sequences) that produce proteins.
The TATA box in eukaryotic cells helps position RNA polymerase, marking the transcription start site.

Operons in Prokaryotic Cells

Operons are groups of genes and regulatory elements that control processes in prokaryotic cells, such as lactose utilization in E. coli.

Role of Proteins

Proteins catalyze reactions and regulate growth rates and patterns, thereby influencing the characteristics of an organism.

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Description

Test your knowledge on key concepts related to DNA and RNA with this set of flashcards. Covering topics such as transformation, bacteriophages, nucleotides, and DNA location in prokaryotes, this quiz is perfect for students in Biology 1. Enhance your understanding of molecular biology fundamentals.