Genetics Shorty

How many codons are located on the messenger RNA molecule in the diagram?

• 1

• 6

• 3

• 9

What does Structure B represent a molecule of?

• nuclear DNA

• cytoplasmic DNA

• ribosomal RNA (rRNA)

• transfer RNA (tRNA)

In the synthesis of proteins, what is the function of messenger-RNA molecules?

• They act as a template for the synthesis of DNA.

• They carry information that determines the sequence of amino acids.

• They remove amino acids from the nucleus.

• They carry specific enzymes for dehydration synthesis.

A sequence of three nitrogenous bases in a messenger-RNA molecule is known as a

• codon

• gene

• polypeptide

• nucleotide

"Nitrogenous bases" - sounds fancy. You say it like this: nie-TROJ-e-nus" You've been reading it a lot - but have you broken in down? Let's see!

Nitrogenous bases means ______?

• That the bases HAVE the element called nitrogen in them.

• That the bases DO NOT HAVE the element called nitrogen in them.

Which base is normally used in the synthesis of RNA but not in the synthesis of DNA?

• adenine (A)

• uracil (U)

• cytosine (C)

• guanine (G)

If a portion of a messenger RNA molecule contains the base sequence A-A-U, the corresponding transfer RNA base sequence is

• A-A-U

• G-G-T

• T-T-C

• U-U-A

What is the complementary messenger-RNA sequence for the DNA sequence shown here?

• C-A-A-G-G-U

• G-T-T-C-C-A

• G-U-U-C-C-A

• C-A-A-G-G-T

When provided with a sequence of bases in one segment of mRNA, the Universal Genetic Code Chart is used to

• directly identify the DNA from an animal cell

• determine the sequence of amino acids in a protein

• change the RNA sequence of a protein into DNA

• identify the specific mutations in the genetic material in a cell

In a cell, protein synthesis is the primary function of

• ribosomes

• mitochondria

• chloroplasts

• vacuoles