Podcast
Questions and Answers
How do histones facilitate DNA packaging in eukaryotes?
How do histones facilitate DNA packaging in eukaryotes?
- By enzymatically cleaving DNA into smaller fragments.
- By neutralizing the negative charge of DNA, allowing tighter packing. (correct)
- By actively unwinding the DNA double helix to reduce its length.
- By providing a negatively charged scaffold for DNA to wrap around.
What is the primary difference between euchromatin and heterochromatin?
What is the primary difference between euchromatin and heterochromatin?
- Heterochromatin is found only in prokaryotes, while euchromatin is exclusive to eukaryotes.
- Heterochromatin consists of DNA, while euchromatin consists of RNA.
- Euchromatin is loosely packed and transcriptionally active, while heterochromatin is tightly packed and generally inactive. (correct)
- Euchromatin contains more genes than heterochromatin.
What is the role of non-histone proteins in metaphase chromosomes?
What is the role of non-histone proteins in metaphase chromosomes?
- To initiate the process of chromosome condensation.
- To provide the primary structural support after histones are removed. (correct)
- To facilitate DNA replication during cell division.
- To protect the telomeres from degradation.
How do the number of genes and biological complexity correlate in organisms?
How do the number of genes and biological complexity correlate in organisms?
What is the significance of alternative splicing in the context of the human genome?
What is the significance of alternative splicing in the context of the human genome?
What is the key characteristic of the bacterial genome that distinguishes it from the eukaryotic genome?
What is the key characteristic of the bacterial genome that distinguishes it from the eukaryotic genome?
What is the primary function of plasmids in bacteria, and how are they useful in biotechnology?
What is the primary function of plasmids in bacteria, and how are they useful in biotechnology?
What is the significance of the 'three-person baby' technique regarding mitochondrial DNA?
What is the significance of the 'three-person baby' technique regarding mitochondrial DNA?
How do retroviruses replicate their genomes, and what enzyme is critical to this process?
How do retroviruses replicate their genomes, and what enzyme is critical to this process?
Considering the composition of the human genome, what proportion is made up of transposable elements?
Considering the composition of the human genome, what proportion is made up of transposable elements?
Flashcards
Genome
Genome
The complete set of DNA within a single cell of an organism.
Genomics
Genomics
The branch of molecular biology concerned with the structure, function, evolution, and mapping of genomes.
Coding Regions
Coding Regions
Regions of a genome that code for proteins or RNA.
Noncoding DNA
Noncoding DNA
Signup and view all the flashcards
Reference Sequence
Reference Sequence
Signup and view all the flashcards
Nucleosome
Nucleosome
Signup and view all the flashcards
Chromatin
Chromatin
Signup and view all the flashcards
Histones
Histones
Signup and view all the flashcards
Heterochromatin
Heterochromatin
Signup and view all the flashcards
Euchromatin
Euchromatin
Signup and view all the flashcards
Study Notes
- The genome represents the complete genetic material within an organism's cell
- It includes DNA (or RNA in RNA viruses), coding regions (genes), noncoding DNA, and the genomes of mitochondria and chloroplasts
- Genomics is the study of the structure, function, evolution, and mapping of genomes
- The human nuclear genome contains approximately 30,000 genes, but less than 2% of the nuclear genome is made up of said genes
- A large portion of the human nuclear genome consists of 27,000 protein-coding genes and roughly 3,000 RNA-coding genes
- Coding DNA makes up 2% of the genome and the remaining 98% is non-coding DNA
- The roundworm C. elegans genome has approximately 19,100 protein-coding genes
- There is no direct correlation between biological complexity and the number of genes an organism possesses
- Ref seq is considered the "wild type" sequence and is the major allele present in the human population
- The organization of the human genome varies by chromosome
- The genome averages approximately 6.7 genes per megabase (Mb).
Amplification of Information Content
- Many genes are capable of being generating creating multiple products due to alternative splicing
- Subsequent biochemical modification of encoded proteins also impacts the end product
- 30,000 human genes encode many hundreds of thousands of different proteins, which are collectively referred to as the proteome
- Proteins operate in networks and respond in a coordinated way to various signals like genetic/developmental/environmental cues
Genes Organization
- Gene families share closely related DNA sequences, encoding polypeptides with closely related amino acid sequences
- Genes arise by duplication of a primitive precursor gene
- Genes may be organized in the following ways:
- Single cluster, all on single chromosomes
- Dispersed, at different chromosome locations
- Multiple cluster, gene clustered on different chromosome
Gene Structure
- Exons are expression sequences
- Introns are intervening sequences
Pseudogenes
- Pseudogenes are sequences with similarities to functional globin and OR genes
- They are non-coding and do not produce functional RNA or protein products
Non-Coding DNA contains:
- Satellite DNA: Large blocks (100 kb to several Mb) of tandemly repeated sequences
- Minisatellite DNA: Moderately-sized blocks (0.1 kb to 20 kb) of tandemly repeated sequences, found in telomere regions (TTAGGG)
- Microsatellite DNA: Small blocks (<100 bp) of tandemly repeated sequences
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
