DNA Structure & Organization

Flashcards covering key concepts of DNA structure and organization from Lecture 10.

What are the two main types of chromatin?

Heterochromatin (highly condensed, no transcription) and Euchromatin (loose, transcription occurs).

What does the nucleolus consist of?

It is a part of the nucleus involved in ribosome biogenesis and rRNA synthesis.

What are CpG islands?

Regions of DNA with a high frequency of the CG sequence, important for gene regulation.

What can histone tail modifications determine?

They can determine how a stretch of chromatin is handled by the cell.

How are human chromosomes visually distinguished in studies?

Each chromosome can be 'painted' a different color for identification.

What occurs to one of the two X chromosomes in mammalian females?

It is inactivated by heterochromatin formation.

What are the effects of acetylation on chromatin?

It causes chromatin to loosen and leads to transcription activation.

What is the significance of DNA double helix structure?

It consists of two polynucleotide chains held by hydrogen bonds between complementary base pairs.

What is the overall structure of a nucleotide?

Each nucleotide is composed of a sugar-phosphate backbone linked to a nitrogenous base.

What is the pathological relevance of histone modification in diseases?

Histone modifications can lead to chromatin condensation and gene silencing, affecting conditions like drug-induced lupus and Huntington's disease.