Bio q&a

What was initially thought to be the carrier of genetic information before DNA was identified?

A ‘vital spark’ or an ‘essence’.

Who conducted the transformation experiment that suggested the presence of a heritable factor?

Frederick Griffith.

What did Avery-MacLeod-McCarty's experiment identify as the ‘transforming factor’?

DNA.

Which experiment confirmed that DNA, not protein, is the hereditary material?

Hershey-Chase Experiment.

Who discovered the double helix structure of DNA?

Watson and Crick.

What are Chargaff’s Rules related to?

Ratios of nucleotide bases: A:T and G:C are approximately 1:1.

What are the three components of a nucleotide?

A nitrogenous base, a deoxyribose sugar, and a phosphate group.

Which base pairs with Adenine (A) in DNA?

Thymine (T).

What is the process of DNA replication called when each parental strand serves as a template?

Semi-Conservative Replication.

What enzyme synthesizes RNA primers during DNA replication?

Primase.

What is the role of DNA Ligase in DNA replication?

Seals gaps between Okazaki fragments.

What term describes the regions of DNA at chromosome ends that are maintained by telomerase?

Telomeres.

What is the basis of the Central Dogma of Molecular Biology?

DNA → RNA → Protein.

What does the one-gene, one-enzyme hypothesis suggest?

Each gene encodes a specific enzyme.

What type of RNA carries the genetic code for protein synthesis?

mRNA (messenger RNA).

What are the three main types of RNA involved in protein synthesis?

mRNA, tRNA (transfer RNA), and rRNA (ribosomal RNA).

What are codons?

Triplets of bases in mRNA that specify amino acids.

Which codon serves as a start signal for translation?

AUG (Methionine).

What is the purpose of the 5′ cap in eukaryotic mRNA?

Aids ribosome binding and stabilizes mRNA.

What are introns?

Non-coding regions of RNA that are removed during splicing.

What type of mutation alters an amino acid in the protein?

Missense mutation.

What are the two types of mutations that shift the reading frame?

Frameshift mutations (insertions or deletions).

What role do transcription factors play in gene regulation?

They bind to DNA and regulate transcription levels of genes.

What does the Lac Operon regulate?

Lactose metabolism.

How does the Trp Operon function in bacterial gene regulation?

It is a repressible operon that turns off when tryptophan levels are high.

What is the role of chromatin organization in eukaryotic gene regulation?

Controls gene accessibility for transcription; heterochromatin is inactive while euchromatin is active.

What is CRISPR-Cas9 primarily used for in genetic engineering?

Precise gene editing.

What are the potential risks associated with genetic engineering?

Safety issues, ethical concerns, and environmental risks.

What is the purpose of Polymerase Chain Reaction (PCR)?

Amplifies small amounts of DNA to millions of copies.

What is totipotency in the context of stem cells?

The ability of cells to differentiate into any cell type.

What is apoptosis and why is it important in development?

Pre-programmed cell death that is crucial for proper organism development.

What are oncogenes?

Mutated genes that promote cancer.

What is a genomic library?

A collection of DNA fragments representing an organism's entire genome.

What does the term biotechnology refer to?

The use of organisms or their components to produce useful products.

What is the significance of the one-gene, one-enzyme hypothesis?

It links specific genes to specific proteins, enhancing our understanding of genetics.

What type of genes are always active and support essential functions in a cell?

Constitutive genes.

What is the difference between inducible and repressible operons in gene regulation?

Inducible operons are turned on by inducers; repressible operons are turned off by end products.

What is the role of ribosomes during translation?

They facilitate the assembly of amino acids into protein chains.

What do release factors do during translation termination?

They recognize stop codons and assist in releasing the completed protein.

What is differential gene expression?

The process by which cells with the same DNA express different genes at different times.

What are the key components of DNA technology?

Restriction enzymes, reverse transcriptase, PCR, gel electrophoresis.

What are stem cells and why are they important?

Undifferentiated cells that can develop into various cell types, important for regenerative medicine.

How does environmental influence affect gene expression?

Environmental factors can lead to changes in gene regulation, impacting development and disease.