Genomes and DNA Flashcards
(60 cards)
What are prokaryotes?
Bacteria and archaea
Prokaryotes are the simplest and most basic life forms, characterized by the absence of a nucleolus.
What are eukaryotes?
More complicated organisms that have organelles, including animals, plants, and fungi
Eukaryotes are generally larger than prokaryotes.
What is the structure of prokaryote genomes?
Circular genome, can be one or many, occasionally linear
Includes plasmids and is compact due to supercoiling.
What is supercoiling in DNA?
Twisting of the DNA structure, can be negative or positive
It results from the addition or removal of turns in the double helix.
What are plasmids?
Extra areas of DNA that can confer antibiotic resistance and the ability to use complex compounds as food
Plasmids can transfer between bacteria, spreading genetic information.
What is a gene?
A sequence of DNA or RNA that codes for a molecule (protein) with a function
Genes are fundamental units of heredity.
What are introns?
Non-coding sections of DNA
They are removed during RNA processing.
What are exons?
Coding sections of DNA
Exons are retained in the final mRNA molecule.
What are retrotransposons?
Elements that copy themselves throughout DNA using reverse transcription, including SINEs, LINEs, and LTRs
They contribute to genome evolution and diversity.
What is a transposon?
DNA that can move around the genome
Transposons are often referred to as ‘jumping genes’.
What is a tandem repeat?
Repeated sections of DNA that occur immediately after each other
They can vary in length and number of repeats.
What is mitochondrial DNA (mtDNA)?
Small, circular DNA located in the mitochondria, containing genes for mitochondrial function
It has a high copy number per cell and is inherited maternally.
What is chloroplast DNA (cpDNA)?
DNA located in chloroplasts, coding for about 200 genes related to photosynthesis
cpDNA is larger than mtDNA and also exhibits low variation due to uni-parental inheritance.
What is the primary role of DNA?
To carry and store genetic information
DNA also serves as a means of passing information down generations.
What are the components of DNA?
A pentose sugar, a nitrogenous base, and a phosphate group
These components form nucleotides, the building blocks of DNA.
What differentiates RNA from DNA?
RNA contains ribose, uracil instead of thymine, and is usually single-stranded
This structural difference impacts their functions in protein synthesis.
What are the types of RNA involved in protein synthesis?
Messenger RNA (mRNA), Transfer RNA (tRNA), Ribosomal RNA (rRNA)
Each type of RNA plays a specific role in the process of translating genetic information into proteins.
What is the central dogma of molecular biology?
The flow of genetic information from DNA to RNA to protein
It describes the processes of transcription and translation.
What is RNA polymerase?
An enzyme that catalyzes the synthesis of RNA from a DNA template
It functions by adding ribonucleotides in the 5’ to 3’ direction.
What are the phases of transcription?
Initiation, elongation, and termination
Each phase involves specific interactions and processes to produce RNA.
What is the TATA box?
A DNA sequence that serves as a promoter for transcription in eukaryotic cells
It is typically located about 25 base pairs upstream of the transcription start site.
What is a molecular marker?
A specific piece of DNA that provides unique information
Molecular markers are used in various applications, including forensic science.
What are the three main types of molecular markers?
Gene regions, SNPs, STRs
Each type has unique applications and characteristics in genetic analysis.
What are STRs?
Short Tandem Repeats, co-dominant markers inherited in a Mendelian fashion
STRs can vary in repeat length and can be used in DNA profiling.
