modern genetics Flashcards
What is the basic unit of protein synthesis?
Amino acid
True or False: DNA is a double-stranded molecule.
True
What process involves copying DNA to produce mRNA?
Transcription
Fill in the blank: The structure of DNA is often described as a __________.
Double helix
What enzyme is responsible for DNA replication?
DNA polymerase
What are the four nucleotide bases in DNA?
Adenine, Thymine, Cytosine, Guanine
Multiple Choice: Which of the following is NOT a type of mutation? A) Substitution B) Insertion C) Deletion D) Duplication E) Translation
E) Translation
What is the main purpose of biotechnology?
To manipulate living organisms or their components for useful purposes.
True or False: The lac operon is involved in the metabolism of lactose in bacteria.
True
What role does RNA play in protein synthesis?
RNA acts as a template for assembling amino acids into proteins.
What type of RNA carries amino acids to the ribosome?
Transfer RNA (tRNA)
Fill in the blank: The sequence of nucleotides in DNA determines the __________ of a protein.
Sequence of amino acids
Multiple Choice: Which of the following is a component of DNA? A) Ribose B) Deoxyribose C) Glucose D) Fructose
B) Deoxyribose
What is the function of messenger RNA (mRNA)?
To convey genetic information from DNA to the ribosome.
True or False: Mutations can be beneficial, harmful, or neutral.
True
What are the three main steps of protein synthesis?
Initiation, elongation, termination
Fill in the blank: The __________ is a segment of DNA that codes for a protein.
Gene
Multiple Choice: Which of the following processes occurs in the nucleus? A) Translation B) Transcription C) Replication D) Both B and C
D) Both B and C
What is the role of the ribosome in protein synthesis?
To facilitate the assembly of amino acids into proteins.
True or False: The lac operon is an example of negative regulation.
True
What are the products of DNA replication?
Two identical DNA molecules
Fill in the blank: A __________ is a change in the nucleotide sequence of DNA.
Mutation
Multiple Choice: Which type of mutation involves the replacement of one base pair? A) Insertion B) Deletion C) Substitution D) Duplication
C) Substitution
What is the significance of the promoter region in a gene?
It is the site where RNA polymerase binds to initiate transcription.
True or False: All mutations lead to changes in protein function.
False
What is the function of the operator in the lac operon?
To regulate the transcription of genes involved in lactose metabolism.
Fill in the blank: In eukaryotes, transcription occurs in the __________.
Nucleus
What is the role of helicase in DNA replication?
To unwind the DNA double helix.
Multiple Choice: Which of the following is NOT a function of proteins? A) Enzymatic activity B) Structural support C) Genetic information storage D) Transport
C) Genetic information storage
What is a silent mutation?
A mutation that does not change the amino acid sequence of a protein.
True or False: The genetic code is universal among all living organisms.
True
What is the first step of transcription?
Binding of RNA polymerase to the promoter.
Fill in the blank: The __________ strand of DNA is used as a template during transcription.
Template
Multiple Choice: Which type of RNA is involved in the formation of ribosomes? A) mRNA B) tRNA C) rRNA D) all of the above
C) rRNA
What is the role of the terminator in transcription?
To signal the end of transcription.
True or False: The genetic code consists of codons that are three nucleotides long.
True
What is the purpose of genetic engineering in biotechnology?
To modify the genetic makeup of organisms for specific traits.
Fill in the blank: The __________ is the part of the DNA molecule that determines the characteristics of an organism.
Gene
Multiple Choice: Which of the following mutations can lead to a frameshift? A) Substitution B) Insertion C) Deletion D) Both B and C
D) Both B and C
What is the role of the sigma factor in prokaryotic transcription?
To assist RNA polymerase in recognizing the promoter.
True or False: The process of translation occurs in the cytoplasm.
True
What is the main difference between DNA and RNA?
DNA contains deoxyribose sugar, while RNA contains ribose sugar.
Fill in the blank: The __________ is the region on a chromosome where the centromere is located.
Centromere
Multiple Choice: What type of mutation results in a premature stop codon? A) Silent B) Missense C) Nonsense D) Frameshift
C) Nonsense
What is the function of the lacZ gene in the lac operon?
To code for beta-galactosidase, which breaks down lactose.
True or False: Eukaryotic genes often contain introns that are spliced out during mRNA processing.
True
What is the role of spliceosomes in gene expression?
To remove introns from pre-mRNA.
Fill in the blank: The __________ is the part of the operon that binds the repressor protein.
Operator
Multiple Choice: What is the outcome of a deletion mutation? A) Extra bases are added B) One or more bases are removed C) A single base is changed D) All of the above
B) One or more bases are removed
What is the significance of the 5’ cap and poly-A tail in mRNA?
They protect mRNA and assist in its export from the nucleus.
True or False: The process of DNA replication is semi-conservative.
True
What is the role of the promoter in gene expression?
It initiates the transcription of a gene.
Fill in the blank: The __________ is a regulatory sequence that enhances transcription.
Enhancer
Multiple Choice: Which molecule carries the genetic code from the nucleus to the ribosome? A) tRNA B) rRNA C) mRNA D) DNA
C) mRNA
What is a frameshift mutation?
A mutation caused by insertions or deletions that shift the reading frame.
True or False: Genetic mutations can occur spontaneously or be induced by environmental factors.
True
What is the role of the repressor in the lac operon?
To inhibit transcription of the operon’s genes when lactose is absent.
Fill in the blank: The __________ is the sequence of nucleotides that codes for a protein.
Coding region
Multiple Choice: What is the primary function of the tRNA molecule? A) To carry genetic information B) To assemble ribosomes C) To transfer amino acids to ribosomes D) To edit mRNA
C) To transfer amino acids to ribosomes
What is the role of the 3’ untranslated region (UTR) in mRNA?
To regulate the stability and translation of mRNA.
True or False: The lac operon is only found in eukaryotic cells.
False
what does DNA ligase do
connects the fragments of the lagging strand