Genetic Information, Variation & Relationships between Organisms Flashcards
(16 cards)
Gene
Section of DNA that contins the coded information for making polypeptides and functional RNA.
Contains the base/nucleotide strucuture in triplets.
This determines the order/sequence of amino acids.
Genes determine the proteins of an organsim.
Locus
Fixed position on a chromosome where a particular gene is located
Degenerate code
Amino acids are coded for by more than one triplet.
The genetic code is…
… non-overlapping
… universal
Non-overlapping
Each base sequence is only read once
Universal
Same triplet code from the same amino acids
Triplets are always read in the same direction along the DNA strand.
Exons
Base nucleotide sequence doing for polypeptide sequence of amino acids.
Describe
How phosphodiester bond is formed between two nucleotides within a DNA molecule
- Between phosphate group and deoxyribose
- Catalysed by DNA polymerase
DNA in the nucleus of a plant cell VS DNA in prokarytoic cell
Plant cell:
- Assoicatated with histones
- Linear
- Contains introns
- Longer
Prokarytoic cell:
- No histones
- Circular
- No introns
- Shorter
Non-coding base sequence
The section of DNA that does not code for a polypeptide chain.
Where is the non-coding regions positioned in the genome?
Positioned between genes.
DNA in chloroplast VS DNA in nucleus in plant cells
Chloroplast:
- DNA is circular
- Shorter
- Fewer genes
- Not associated with histones
Nucleus:
- DNA is linear
- Longer
- Associated with histones.
Why does not all mutations in nucleotide sequence not cause a change in the strucutre of a polypeptide
- Triplets code for the same amino acid - degenerate
- Occurs in introns/non-coding region
Compare & Contast
Eukaryotic DNA vs Prokaryotic DNA
Similarities:
- Nucleotide structure is identical
- Nucleotides join by phosphodiester bond
Differences:
- Eukaryotic DNA is assoicated with histones
- Eukaryotic DNA is longer
- Eukarytoic DNA is linear
- Eukarytoic DNA contains introns.
Prokarytoic DNA does not/shorter/circular.
Why does some stains bind more in chromosomes in some areas?
- Differences in base sequence
- Differences in histones
Homologous chromosomes
A pair of chromosomes that have the same genes but carry differnt alleles.
One is inheritied from the mother and the other from the father
