Genetics: Spacer Molecules, Promoters, Telomere, and Centromere

Play an AI-generated podcast conversation about this lesson

What is the function of a centromere during mitosis and meiosis?

Anchors the chromosome to the spindle fibers (correct)

Records the number of cell divisions

Protects RNA from degradation

Contains highly repeated sequences like (TTAGGG)n

Which molecules signal and control transcription in gene sequences?

Exons

Introns

Telomeres

Promoters/enhancers (correct)

What is the primary role of the tail added to hnRNA at its 3’-end?

Encodes stop codons

Initiation of protein synthesis

Prevents degradation of RNA (correct)

Acts as a spacer in gene sequences

How do exons differ from introns in gene sequences?

Exons separate coding genes, introns loop out prior to protein synthesis Signup and view all the answers

What kind of sequences are found in telomeres that serve as aging markers?

(TTAGGG)n repeats Signup and view all the answers

During hnRNA synthesis, what is the role of the GTP cap added to the 5’-end?

Initiates protein synthesis Signup and view all the answers

What type of proteins aid in looping out the introns during mRNA formation from hnRNA?

Small nuclear proteins Signup and view all the answers

In the context of protein synthesis, what is the role of N,N’-dimethyl guanine in tRNA?

Helps in twisted conformation of tRNA for amino acid transportation Signup and view all the answers

What is the specific function of the acceptor stem in tRNA?

Carrying the amino acid Signup and view all the answers

Which RNA type is directly involved in protein formation from mRNA?

mRNA Signup and view all the answers

What is the primary function of the anticodon site on tRNA?

Binding to a 3-base codon of mRNA Signup and view all the answers

Which region of tRNA first binds to its corresponding amino acid before entering the ribosome for protein synthesis?

Acceptor stem (3’ end) Signup and view all the answers

What is the role of p53, p63, and p73 in inhibiting cyclinD/CDK4 complex?

Cause the synthesis of mRNA for p21, a protein that inhibits cyclinD/CDK4 Signup and view all the answers

How does an defect in p53 affect the cell cycle?

Allows uncontrolled cell division by cyclinD/CDK4 complex Signup and view all the answers

What is the significance of CDK4 in cell cycle progression?

Influences the division ability of cells to enter S phase Signup and view all the answers

What is the primary function of heat shock proteins in an organism?

Solubilizing and refolding any heat-denatured proteins Signup and view all the answers

How do E2F and Rb proteins influence the cell cycle progression?

Facilitate passage from G1 to S phase by binding and releasing each other Signup and view all the answers

What is the number of genes and exons for Alpha-crystallin?

2 genes with 3 exons per gene Signup and view all the answers

What is the role of RNA primase in DNA replication?

Synthesizes short strands of primer RNA Signup and view all the answers

Which enzyme is responsible for completing the gaps between DNA Okazaki fragments?

Ligase enzyme Signup and view all the answers

What is the function of Transfer RNA (tRNA) in protein synthesis?

Attaches to specific amino acids and transports them to ribosomes Signup and view all the answers

What is the primary function of Ribosomal RNA (rRNA) in protein synthesis?

Represents 75% of all RNA in a cell Signup and view all the answers

Which type of RNA represents the most common occurrence and what percentage of RNA does it make up?

Ribosomal RNA (rRNA); 75% Signup and view all the answers

What is the primary role of telomeres in preserving chromosome integrity?

Recording the number of cell divisions as an aging marker Signup and view all the answers

Which of the following is a characteristic of hnRNA?

Looped out of a coding sequence prior to protein synthesis Signup and view all the answers

What is the function of the GTP cap added at the 3’-end of hnRNA before mRNA synthesis?

Protects RNA from degradation Signup and view all the answers

In gene sequences, what differentiates introns from exons?

Exons loop out of coding sequences before protein synthesis, while introns remain intact Signup and view all the answers

What type of sequences are highly repeated in mammalian telomeres?

(TTAGGG)n Signup and view all the answers

What is the role of the GTP cap added to hnRNA at the 5’-end?

Aids in splicing out introns during mRNA formation Signup and view all the answers

What is the significance of CDK4 in the context of protein synthesis?

Regulates cell cycle progression and inhibits protein synthesis Signup and view all the answers

How do E2F and Rb proteins influence mRNA formation from hnRNA?

Regulate transcriptional activation and repression Signup and view all the answers

In the context of genetic code, what is the function of a stop codon?

Signals the termination of protein synthesis Signup and view all the answers

What type of proteins aid in telomere maintenance and serve as aging markers?

Telomerase proteins Signup and view all the answers

What is the specific function of regulatory proteins in hnRNA synthesis?

Inhibiting the initiation of hnRNA synthesis Signup and view all the answers

Where does RNA polymerase bind to initiate transcription?

To the minor groove of DNA Signup and view all the answers

What does a stop code indicate in the genetic code?

The termination of protein synthesis Signup and view all the answers

What are the diverse roles of noncoding regions in DNA?

Contributing to regulation of gene expression and chromatin structure Signup and view all the answers

What kind of sequences are typically found in telomeres and serve as aging markers?

Guanine repeats Signup and view all the answers

What is the catalytic activity responsible for peptide bond formation in the ribosome?

23S rRNA catalytic activity Signup and view all the answers

Which photoproduct is formed when adjacent pyrimidines bond due to UV exposure, distorting the DNA helix?

6-4 photoproduct Signup and view all the answers

What is the primary role of telomeres in a cell's genetic material?

Protect chromosome ends from deterioration and fusion Signup and view all the answers

What is the primary function of regulatory proteins in hnRNA synthesis?

Control initiation and elongation of RNA polymerase Signup and view all the answers

How does the turnover rate of proteins relate to mRNA molecules?

Multiple proteins can be formed from one mRNA molecule Signup and view all the answers

What is the primary function of telomeres?

Prevent degradation and unnecessary recombination of DNA Signup and view all the answers

In hnRNA synthesis, what is the specific role of regulatory proteins?

Protect the newly transcribed RNA molecule from degradation Signup and view all the answers

What is the significance of noncoding DNA regions in the genome?

They regulate gene expression and play a role in cell differentiation Signup and view all the answers

Which statement best describes the genetic code and its relation to stop codons?

Specific sets of 3 bases in the genetic code act as stop codons Signup and view all the answers

During transcription, what is the main role of RNA polymerase regarding binding to DNA?

Recognizes specific promoter sequences to initiate transcription Signup and view all the answers

What is the main function of regulatory proteins in hnRNA synthesis?

Promote mRNA splicing Signup and view all the answers

What is the role of RNA polymerase in gene expression?

Facilitating transcription Signup and view all the answers

Which codon signals for the termination of protein synthesis?

UAA Signup and view all the answers

What are the main roles of noncoding DNA regions?

Regulate gene expression Signup and view all the answers

Which component is repeated at the ends of linear chromosomes to protect them from degradation?

Telomeres Signup and view all the answers

What is the significance of the TTAGGG sequence in telomeres?

Prevent chromosome shortening Signup and view all the answers

What is the effect of a mutation in the stop codon sequence?

Results in premature termination of translation Signup and view all the answers

How do telomeres contribute to maintaining genome stability?

Prevent chromosomal fusions and degradation Signup and view all the answers

What is the primary function of noncoding regions in DNA?