Biology Processes in Sales and Genetics

Review essential concepts related to genetics, DNA replication, transcription, and mutation that are key for the upcoming exam.

What is the purpose of DNA replication in a cell?

To make a copy of the DNA so that new cells have the same genetic information.

What is transcription in genetics?

The process through which DNA is converted into messenger RNA (mRNA).

What is the role of tRNA?

Transfer RNA (tRNA) brings the appropriate amino acids to the ribosome during protein synthesis.

What does the genetic code table represent?

It translates mRNA codons into corresponding amino acids.

What are exons and introns?

Exons are parts of a gene that are expressed, while introns are non-coding segments that are removed during RNA processing.

What is a start codon, and what role does it play?

The start codon (AUG) signals the beginning of protein synthesis.

What is a stop codon? Provide an example.

A stop codon signals the end of protein synthesis. An example is UGA.

What effect does a mutation have on a cell?

A mutation is a permanent change in the DNA sequence that may affect the protein produced.

What is an operon?

A segment of DNA containing a cluster of genes that are regulated together.

Differentiate between missense mutation and nonsense mutation.

A missense mutation results in a change in amino acid sequence; a nonsense mutation leads to premature termination of protein synthesis.

What is transformation in bacteria?

The genetic alteration of a bacterial cell by uptake and expression of foreign DNA.

What is conjugation in bacteria?

A process where one bacterium transfers genetic material to another through direct contact.

What is transduction in genetic terms?

The process by which DNA is transferred from one bacterium to another by a virus.

What are chemical mutagens?

Agents that can induce mutations in DNA, often found in the environment or used in research.

What is the significance of plasmids in bacteria?

Plasmids are small circular pieces of DNA that can carry genes for antibiotic resistance and can be transferred between bacteria.

What does the term ‘mobile genetic elements’ refer to?

DNA segments that can move within the genome, often including plasmids and transposons.

Explain the difference between ionizing and non-ionizing radiation in terms of DNA damage.

Ionizing radiation causes permanent DNA damage by breaking DNA backbones, while non-ionizing radiation, like UV, causes less severe effects such as thymine dimers that can sometimes be repaired.

What role do photolyases play in DNA repair?

Photolyases are enzymes that repair thymine dimers caused by UV radiation.

How can scientists utilize reverse transcriptase?

Reverse transcriptase converts RNA back into DNA, allowing for the creation of complementary DNA from RNA templates.