DNA and RNA Overview

Flashcards covering key concepts related to DNA structure, replication, RNA function, protein synthesis, gene regulation, and mutations.

What did Griffith discover in 1928 regarding bacteria?

He discovered transformation in bacteria, where harmless bacteria became deadly when mixed with heat-killed harmful bacteria.

What did Avery demonstrate in 1944?

Avery showed that DNA caused transformation in bacteria.

What was the key finding of Hershey and Chase in 1952?

They proved that DNA is the genetic material by using viruses with radioactive DNA and protein.

Who was Rosalind Franklin and what was her contribution to DNA research?

Franklin used X-ray diffraction to take images of DNA's helical structure.

What did Watson and Crick achieve in 1953?

They built the double-helix model of DNA using Franklin's images, though they did not discover DNA.

What are the three parts of a nucleotide?

Sugar (deoxyribose), phosphate group, and nitrogen base (A, T, C, G).

What forms the backbone of the DNA structure?

The sugar and phosphate groups form the backbone of the DNA.

What connects the rungs of the DNA ladder?

The nitrogen bases connect in the middle by hydrogen bonds (A-T, C-G).

What is the role of helicase during DNA replication?

Helicase unzips the DNA strands.

What happens during the S phase of interphase?

DNA replication occurs, resulting in two identical DNA molecules.

What are the main differences between DNA and RNA?

1. Sugar: DNA = deoxyribose; RNA = ribose. 2. Bases: DNA has thymine; RNA has uracil. 3. Structure: DNA is double-stranded; RNA is single-stranded.

What is uracil and when is it used?

Uracil (U) replaces thymine (T) in RNA, pairing with adenine.

What is the definition of a gene?

A gene is a section of DNA that codes for a protein.

What is transcription?

Transcription is the process of building an mRNA strand from one DNA strand.

What is translation in the context of protein synthesis?

Translation is the process where ribosomes read mRNA codons and tRNA brings matching amino acids to form a polypeptide.

What are transcription factors?

Proteins that bind to DNA to start or stop transcription, controlling gene expression.

What is epigenetics?

The study of changes that affect gene activity without changing the DNA sequence.

What are the types of mutations?

Sequence mutations (changes in base order) and chromosomal mutations (changes in structure or number of chromosomes).

What are the two types of chromosomal mutations?

1. Deletion: Part missing. 2. Duplication: Extra copy.

What is nondisjunction and what can it cause?

Nondisjunction is an error in meiosis that can lead to an abnormal number of chromosomes, such as Down syndrome.