4.1 DNA, Genes & Chromosomes Flashcards
What is a gene?
A section of DNA that codes for a protein which controls a characteristic
What is a chromosome?
A long piece of DNA containing many genes, supercoiled so it fits into the nucleus
What are histones?
Proteins that supercoil
How many chromosomes do humans have in their somatic cells?
46 (23 pairs)
What are somatic cells?
Cell of a living organism other than the reproductive cells
Where in the cell are chromosomes stored?
Nucleus
Why is the order of DNA bases important for the production of a protein?
The order of bases will determine the order of amino acids
The order of amino acids will determine where bonds form
Where bonds form will determine the structure of the protein
How many bases code for one amino acid?
3
What does degenerate mean?
Some amino acids have more than one codon or triplet
What does non-overlapping mean?
A base can only be part of one codon
What does universal mean?
All organisms use the same DNA code
How can the size of a protein be calculated?
number of base pairs / 3 = number of amino acids
Compare eukaryotic and prokaryotic DNA.
Eukaryotic is linear Prokaryotic is circular
Eukaryotic has associated histones Prokaryotic is naked
Eukaryotic is longer
Eukaryotic has introns Prokaryotic does not
Both use the same nucleotide structure
DNA in mitochondria and chloroplasts is very similiar to prokaryotic
How much of the DNA codes for proteins?
4%
What is an intron?
A non-coding piece of DNA within a gene
