Gene Expression and Cell Specialization - AP Biology
- Identify the process by which cells become specialized.
- Cell differentiation. Cells express different genes to develop unique functions.
- Identify the enzyme that synthesizes RNA from a DNA template.
- RNA polymerase. It reads DNA template and synthesizes complementary RNA strands.
- What is the genetic code and its key feature?
- Set of codons; it is universal and redundant. Multiple codons can specify the same amino acid.
- What is the effect of a mutation in a gene's coding sequence?
- It may alter the protein's function. Changes in DNA sequence can change amino acid sequence.
- State the function of the genetic code's redundancy.
- Minimizes the effects of mutations. Multiple codons for one amino acid reduce mutation impact.
- What is a codon?
- A sequence of three nucleotides in mRNA. It specifies which amino acid to add during translation.
- What is the role of tRNA during translation?
- tRNA brings amino acids to the ribosome. Each tRNA carries a specific amino acid matching its anticodon.
- Find the complementary RNA sequence to DNA: 5'-ATCG-3'.
- 5'-UAGC-3'. A pairs with U, T with A, C with G, G with C.
- State the start codon used in protein synthesis.
- AUG. This codon signals where protein synthesis begins.
- Find and correct the error: DNA is translated to RNA.
- Correct: DNA is transcribed to RNA. Translation converts RNA to protein, not transcription.
- What is the role of a promoter in gene expression?
- A promoter initiates transcription. It's the DNA sequence where RNA polymerase binds.
- What are introns and what happens to them during RNA processing?
- Introns are removed from pre-mRNA. Non-coding sequences spliced out during RNA processing.
- State the sequence of events in protein synthesis.
- Initiation, elongation, termination. The three main phases of both transcription and translation.
- Identify the RNA sequence transcribed from DNA: 3'-TACG-5'.
- 5'-AUGC-3'. Template strand read 3' to 5' produces 5' to 3' RNA.
- What is the outcome of alternative splicing?
- Different proteins from the same gene. Increases protein diversity from limited number of genes.
- Identify the type of bond formed between amino acids.
- Peptide bond. Covalent bond linking amino acids in protein chains.
- What is the function of the TATA box in transcription?
- It is a DNA sequence indicating a start site. Promoter element that helps position RNA polymerase.
- What is the role of chaperone proteins?
- They assist protein folding. They prevent misfolding and help proteins reach native structure.
- What is the function of ribosomes in cells?
- Ribosomes facilitate protein synthesis. They read mRNA and assemble amino acids into proteins.
- Which process follows transcription in eukaryotic cells?
- RNA processing. mRNA must be processed before leaving the nucleus.
- What is the role of spliceosomes in gene expression?
- Spliceosomes remove introns from pre-mRNA. They cut out non-coding sequences from RNA transcripts.
- Which type of RNA carries the genetic code from DNA to the ribosome?
- mRNA. It's the messenger that transfers genetic information.
- What is meant by 'gene expression'?
- Conversion of gene information into a product. When genes are transcribed and translated into proteins.
- What is the purpose of the 5' cap in mRNA?
- Protection and initiation of translation. Modified guanosine that protects and facilitates translation.
- Which molecule is the end product of transcription?
- RNA. DNA is transcribed into RNA, not protein directly.
- Which process converts genetic information from DNA to RNA?
- Transcription. DNA serves as template to create RNA copy of gene.
- What is an operon?
- A cluster of genes under a single promoter. Allows coordinated regulation of related genes in prokaryotes.
- Which cellular organelle is the site of translation?
- Ribosome. Where mRNA is decoded into polypeptide chains.
- What binds to an operator to regulate gene expression in prokaryotes?
- Repressor protein. It blocks RNA polymerase from transcribing genes.
- What is the function of a poly-A tail in mRNA?
- Stability and export from the nucleus. Protects mRNA from degradation and aids nuclear export.
- What is the function of enhancers in gene expression?
- Enhancers increase transcription rates. They bind to DNA and boost gene transcription.
- Identify the process that translates mRNA into a polypeptide.
- Translation. It converts mRNA sequence into amino acid sequence.
- What is the role of transcription factors?
- They regulate the transcription of genes. Proteins that control when genes are turned on/off.
- What is the primary function of mRNA in gene expression?
- mRNA serves as a template for protein synthesis. It carries genetic instructions from nucleus to ribosomes.
- Which process involves the removal of introns?
- RNA splicing. It removes non-coding introns from pre-mRNA transcripts.
- Which type of RNA forms the structural and catalytic part of the ribosome?
- rRNA. It's the catalytic component that forms peptide bonds.