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

1. translation.

2. transcription.

3. transformation.

4. replication.

Which of the following describes RNA?

1. RNA is usually double-stranded and contains the base thymine.

2. RNA is usually single-stranded and contains the base uracil.

3. RNA is longer than DNA and uses five bases to encode information.

4. RNA is made in the nucleus of eukaryotic cells and stays there to carry out its functions.

Describe the function of each of the three types of RNA.

How does the enzyme that makes RNA know where to start transcribing the DNA?

Compare introns and exons.

Apply Concepts Suppose you start with the DNA strand ACCGTCAC. Use the rules of base pairing to list the bases on a messenger RNA strand transcribed from this DNA strand.

Predict Look at the first intron in the diagram below. What would happen to the protein produced by the mRNA molecule if the intron were not removed but functioned instead as an exon?

In messenger RNA, each codon specifies a particular

• nucleotide.

• enzyme.

• amino acid.

• promoter.

The number of codons in the genetic code is

• 3.

• 4.

• 20.

• 64.

Which of the following statements about the genetic code is true?

• A codon can specify more than one amino acid.

• Every codon specifies a different amino acid.

• Some codons specify the same amino acid.

• Some codons have no function at all.

The process of making proteins on the ribosome based on instructions from messenger RNA is called

• transcription.

• transformation.

• translation.

• molecular biology.

What is a codon?

How do anticodons function?

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

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

Use Analogies The word transcribe means “to write out.” The word translate means “to express in another language.” Review the meanings of transcription and translation in genetics. How do the technical meanings of these words relate to the everyday meanings of the words?

Predict A researcher identifies the nucleotide sequence AAC in a long strand of RNA inside a nucleus. In the genetic code, AAC codes for the amino acid asparagine. When that RNA becomes involved in protein synthesis, will asparagine necessarily appear in the protein? Explain your answer.