Genetic Info, Variation & Relationships 3.4 Flashcards
DNA, genes and chromosomes (AO1)
Describe the structure of prokaryotic DNA
Circular;
No introns;
Not associated with histones;
Short;
Plasmids;
DNA, genes and chromosomes (AO1)
Which organelles contain DNA with the same structure as prokaryotes
Mitochondria
Chloroplasts
DNA, genes and chromosomes (AO1)
Describe the structure of eukaryotic DNA
Linear;
Introns;
Associated
with histones;
Long;
DNA, genes and chromosomes (AO1)
DNA molecule and its associated proteins (e.g. histones) form a _______________.
chromosome
DNA, genes and chromosomes (AO1)
Differences between DNA in the nucleus of a plant cell vs. DNA in a prokaryotic cell.
1. Associated with histones v no histones;
2. Linear v circular;
3. No plasmids v plasmids;
4. Introns v no introns;
5. Longer v shorter;
DNA, genes and chromosomes (AO1)
Define a gene
A sequence of DNA bases that codes for a polypeptide
DNA, genes and chromosomes (AO1)
In addition to polypeptides, what can genes also code for?
ribosomal (rRNA)
&
transfer (tRNA)
DNA, genes and chromosomes (AO1)
Define locus
Fixed position of a gene on a
chromosome / DNA molecule
DNA, genes and chromosomes (AO1)
Define homologous chromosomes
Carry the same genes
(but different alleles)
DNA, genes and chromosomes (AO1)
In eukaryotic DNA, genes contain _______ and _______.
introns
and
exons
DNA, genes and chromosomes (AO1)
Define exon
DNA base sequences that code for sequence of amino acids
DNA, genes and chromosomes (AO1)
Define intron
DNA base sequences that DO NOT code for sequence of amino acids
DNA, genes and chromosomes (AO1)
TRUE or FALSE:
In eukaryotes, much of the nuclear DNA does not code for polypeptides.
TRUE
e.g. only 1% of human DNA contains genes that code for polypeptides
DNA, genes and chromosomes (AO1)
Location of non-coding multiple repeats of DNA base sequences.
between genes
OR
intergenic
DNA, genes and chromosomes (AO1)
Define non-coding
DNA that does not code for polypeptides
OR
DNA that does not code for sequences of amino acids
DNA & Protein Synthesis (AO1)
Define genome
All the DNA in a cell
DNA & Protein Synthesis (AO1)
Define proteome
The full range of proteins produced by cells
DNA, genes and chromosomes (AO1)
A sequence of three DNA bases, called a _________________ , codes for a specific amino acid.
triplet
DNA, genes and chromosomes (AO1)
A sequence of three RNA bases, called a _________________ , codes for a specific amino acid.
codon
DNA, genes and chromosomes (AO1)
TRUE or FALSE:
Within a gene, there can be multiple introns.
TRUE
There can also be multiple exons
DNA, genes and chromosomes (AO1)
A DNA triplet has the bases ACT, what are the bases in the mRNA codon?
UGA
DNA, genes and chromosomes (AO1)
The genetic code is ‘universal’.
Define this term.
The same 3 bases used in DNA triplets code for the same amino acid in all organisms
OR
The same 3 bases used in mRNA codons code for the same amino acid in all organisms
DNA, genes and chromosomes (AO1)
The genetic code is ‘non-overlapping’.
Define this term.
Each DNA base is read only once in the triplet
OR
Each base is read only once in the codon
DNA, genes and chromosomes (AO1)
The genetic code is ‘degenerate’.
Define this term.
More than one codon / triplet codes for a single amino acid