In: Biology
1, DNA polymerase a. adds new nucleotides to a strand. b. proofreads DNA strands to see that they are correct. c. makes rare mistakes resulting in mutation. d. is an enzyme. e. is all of thes
2.The three “stop” codons cause what to happen? a. They cause the ribosome to stop building a protein. b. They instruct ribosomes to build proteins. c. They initiate DNA replication. d. They code for three amino acids.
3 True-False. Messenger RNA is the same length as the entire chromosome. True False In transcription in eukaryotic cells, RNA polymerase: a. cannot function until the two sides of the entire chromosome have completely separated. b. 5′ caps are removed from the messenger RNA. c. needs RNA primase to lay down 5-10 RNA nucleotides as a primer. d. cuts the hydrogen bonds holding together DNA base pairs A-T and G-C.
4.Which is FALSE concerning a codon? a. a single codon never codes for more than one amino acid. b. two or more codons may code for the same amino acid. c. codons are unique to each species. d. a single codon consists of three nucleotides.
5,The anti-codon of individual transfer RNA molecules is a. the part of transfer RNA that bonds to a specific amino acid. b. complementary to the corresponding codon in ribosomal RNA. c. complementary to the corresponding codon in messenger RNA. d. the “stop” codon
which ends translation of an mRNA strand.
1. DNA polymerase
a. adds new nucleotides to a strand.
b. proofreads DNA strands to see that they are correct.
c. makes rare mistakes resulting in mutations.
d. is an enzyme.
e. is all of these
Answer and Explanation: The correct option is (e) It is all of these.
DNA polymerase is responsible for synthesizing new DNA strands on a template strand through a process called DNA replication. These are enzymes that are also involved in proofreading and repair processes. Failure to repair or any mistake can lead to mutations.
2. The three “stop” codons cause what to happen?
a. They cause the ribosome to stop building a protein.
b. They instruct ribosomes to build proteins.
c. They initiate DNA replication.
d. They code for three amino acids.
Answer and Explanation: The correct option is (a) They cause the ribosome to stop building a protein.
Codons are nucleotide triplets that codes for amino acid and thus help in translation that is builiding polypeptide sequences ultimately leading to forming a protein. STOP codons, however, do not code for any amino acids and thus are used as termination factors for the process of Translation.
3 True-False. Messenger RNA is the same length as the entire chromosome.
Answer and Explanation: False
messenger RNA or mRNAs are shorter than the DNA as the Chromosome contains the entire code for making a lot of functional proteins as well as regulatory proteins. mRNA contains code for just a single protein or a part of the protein.
Q.In transcription in eukaryotic cells, RNA polymerase:
a. cannot function until the two sides of the entire chromosome have completely separated.
b. 5′ caps are removed from the messenger RNA.
c. needs RNA primase to lay down 5-10 RNA nucleotides as a primer.
d. cuts the hydrogen bonds holding together DNA base pairs A-T and G-C.
Answer and Explanation: The correct option is (d) Cuts the hydrogen bonds holding together DNA base pairs A-T and G-C
RNA polymerases basically synthesize a messenger RNA from a DNA template. It is involved in locally unwinding the DNA duplex by breaking their H bonds.
4. Which is FALSE concerning a codon?
a. a single codon never codes for more than one amino acid.
b. two or more codons may code for the same amino acid.
c. codons are unique to each species.
d. a single codon consists of three nucleotides.
Answer and Explanation: The correct option is (a) A single codon never codes for more than one amino acid is False.
Codons are degenerate, which means that there is more than one codon for each amino acid. However, a single codon cannot code for more than one amino acid. Each codon codes for only a single amino acid, that is they are non-ambiguous.
5. The anti-codon of individual transfer RNA molecules is
a. the part of transfer RNA that binds to a specific amino acid.
b. complementary to the corresponding codon in ribosomal RNA.
c. complementary to the corresponding codon in messenger RNA.
d. the “stop” codon which ends the translation of an mRNA strand.
Answer and Explanation: The correct option is (c), Anticodon of an individual transfer RNA molecule is complementary to the corresponding codon in messenger RNA.
This is important for the correct formation of the polypeptide chain and thus ultimately the protein.
I hope you got the answers.