DNA & Genes Flashcards
Describe the structure of DNA in prokaryotes
- Short and circular chromosomes
- DNA is located in the Cytoplasm
- Supercoiled
Describe the process of supercoiling
Supercoiling is the process by which the circular chromosomes condenses to fit inside the cell.
Describe the structure of DNA in Eukaryotes
- Long and linear
- Contain homologous pairs
- located in the nucleus
- Wrap around proteins called histones then condenses to the chromosome
What does Homologous mean?
The chromosome from the mother and father have the same genes at the same loci but alleles might be different at those loci.
What is the name given to chromosomes in diploid eukaryotes?
Homologous pairs
What is the endosymbiotic theory?
The theory states that bacterial cells were engulfed by a larger cell during evolution.
What does the DNA in chloroplasts encode?
Enzymes for Photosynthesis
What does the DNA in mitochondria encode?
Enzymes for Respiration.
Why do prokaryotic chromosomes supercoil?
Fit inside the cell
What 4 different bases are DNA made from?
(A, T, C, G).
Gene
a sequence of bases in DNA.
Locus
Specific location of a gene in the DNA
Codon/Triplet
Three bases in a gene that encode a specific amino acid.
mRNA
The RNA molecule that is copied into a polypeptide.
tRNA
The RNA molecule that helps find the correct amino acids for specific codon.
The three important features of the genetic code
Non-overlapping
Universal
Degenrate
What are non-coding multiple repeats useful for
for forensic testing and paternity tests.
Introns
The non-coding regions in a gene.
Exons
coding regions in a gene
What do RNA and DNA have in common?
Both contain 4 different nucleotides
Compare and contrast the similarities and differences between eukaryotic and prokaryotic DNA.
- Eukaryotics have long and linear chromosomes with DNA wrapped around histones.
- Prokaryotes have single, circular chromosomes.
- Prokaryotes pack their chromomes by supercoiling managed by DNA gyrase
What does compartmentalisation enable in eukaryotes?
To build more complex proteins and RNA products
What does compartmentalisation enable in prokaryotes?
RNA and protein synthesis occur more quickly
What cell structures does not contain heritable information?
Cytoplasmic membrane
