Replication and Gene Expression Quizlet Cards

What is the initial mechanism for repairing nucleotide errors in DNA? (A) DNA polymerase proofreading (B) Mismatch repair (C) Nucleotide excision repair (D) Thymine dimers

Answer Choice: A

Reading Frame

Sequence of triplet codons in mRNA that specify a particular protein; a ribosome shift of one or two nucleotides in either direction completely abolishes synthesis of that protein

DNA polymerase reads the template strand in the 3' to 5' direction and adds nucleotides only in the 5' to 3' direction. The leading strand is synthesized in the direction away from the replication fork. Replication on the lagging strand occurs in the direction of the replication fork in short stretches of DNA called Okazaki fragments. True or false?

False. DNA polymerase reads the template strand in the 3' to 5' direction and adds nucleotides only in the 5' to 3' direction. The leading strand is synthesized in the direction of the replication fork. Replication on the lagging strand occurs in the direction away from the replication fork in short stretches of DNA called Okazaki fragments.

DNA replication takes place from 3' to 5'. True or false?

False. DNA replication takes place from 5' to 3'.

Missense is the type of point mutation that would result in the substitution of a stop codon for an amino acid. True or false?

False. Nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon.

Upstream

Nucleotides preceding the initiation site; in general, sequences toward the 5' end relative to a site on the mRNA

Splicing

Process of removing introns and reconnecting exons in a pre-mRNA

Signal Sequence

Short tail of amino acids that directs a protein to a specific cellular compartment

Transcription Bubble

Strand of DNA that specifies the complementary mRNA molecule

Anticodon

Three-nucleotide sequence in a tRNA molecule that corresponds to an mRNA codon

DNA is made up of two strands that are twisted around each other to form a helix. Adenine pairs up with thymine and cytosine pairs with guanine. The two strands are antiparallel in nature; that is, the 3' end of one strand faces the 5' end of other strand. Sugar, phosphate, and nitrogenous bases contribute to the DNA structure. True or false?

True.

DNA polymerase I removes the RNA primers from the developing copy of DNA. DNA ligase seals the ends of the new segment, especially the Okazaki fragments. True or false?

True.

During proofreading, DNA polymerase reads the DNA. True or false?

True.

Start Codon

AUG (or rarely, GUG) on an mRNA from which translation begins; always specifies methionine

What is the flow of information for the synthesis of proteins according to the central dogma? (A) DNA to mRNA to protein (B) DNA to mRNA to tRNA to protein (C) DNA to protein to mRNA to protein (D) mRNA to DNA to mRNA to protein

Answer Choice: A

What would happen if the 5' methyl guanosine was not added to an mRNA? (A) The transcript would degrade when the mRNA moves out of the nucleus to the cytoplasm. (B) The mRNA molecule would stabilize and start the process of translation within the nucleus of the cell. (C) The mRNA molecule would move out of the nucleus and create more copies of the mRNA molecule. (D) The mRNA molecule would not be able to add the poly-A tail on its strand at the 5' end.

Answer Choice: A

A poly-A sequence is added at the: (A) 5' end of a transcript in the nucleus (B) 3'-end of a transcript in the nucleus (C) 5' end of a transcript in the cytoplasm (D) 3'-end of a transcript in the cytoplasm

Answer Choice: B

The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code explains this? (A) Complementarity (B) Degeneracy (C) Nonsense codons (D) Universality

Answer Choice: B

How many nucleotides are in 12 mRNA codons? (A) 12 (B) 24 (C) 36 (D) 48

Answer Choice: C

What are Autonomously Replicating Sequences (ARS)? (A) Areas of prokaryotic chromosomes that initiate copying (B) Portions of prokaryotic chromosomes that can be transferred from one organism to another (C) Areas of eukaryotic chromosomes that are equivalent to the origin of replication in E. coli (D) Portions of eukaryotic chromosomes that replicate independent of the parent chromosome

Answer Choice: C

What are introns? (A) DNA sequences to which polymerases bind (B) The processed mRNA (C) Translated DNA sequences in a gene (D) Untranslated DNA sequences in a gene

Answer Choice: D

What type of body cell does not exhibit telomerase activity? (A) Adult stem cells (B) Embryonic cells (C) Germ cells (D) Liver cells

Answer Choice: D

Where are the RNA components of ribosomes synthesized? (A) Cytoplasm (B) Endoplasmic Reticulum (C) Nucleus (D) Nucleolus

Answer Choice: D

Promoter

DNA sequence to which RNA polymerase and associated factors bind and initiate transcription

Replication of the lagging strand occurs in the direction away from the replication fork in short stretches of DNA, since access to the DNA is always from the 5' end. This results in pieces of DNA being replicated in a discontinuous fashion. True or false?

False. Replication of the lagging strand occurs in the direction away from the replication fork in short stretches of DNA, since access to the DNA is always from the 3' end. This results in pieces of DNA being replicated in a discontinuous fashion.

The amount of adenine, thymine, guanine, and cytosine varies from species to species and are found in equal quantities. They do not vary between individuals of the same species and can be used to identify different species. True or false?

False. The amount of adenine and thymine is equal to guanine and cytosine and is found in equal quantities. They do not vary between individuals of the same species and can be used to identify different species.

The ends of the linear chromosomes are maintained by primase. True or false?

False. The ends of the linear chromosomes are maintained by telomerase.

Initiator tRNA

In prokaryotes, called tRNA f Met ; in eukaryotes, called tRNAi - a tRNA that interacts with a start codon, binds directly to the ribosome P site, and links to a special methionine to begin a polypeptide chain

Exon

Sequence present in protein-coding mRNA after completion of pre-mRNA splicing

This was why radioactive sulfur and phosphorus were used to label bacteriophages in the Hershey and Chase experiment: Protein was labeled with radioactive sulfur and DNA was labeled with radioactive phosphorus. Phosphorus is found in DNA, so it will be tagged by radioactive phosphorus. True or false?

True.