Topic 4 - Key words - DNA, RNA and protein synthesis Flashcards
Gene
A sequence of DNA that codes for a polypeptide or a functional RNA
Locus
The location of a gene on a chromosome
DNA triplet
A sequence of 3 DNA bases that code for a specific amino acid
Universal
The genetic molecule in all living organisms (GGT codes for glycine in all living organisms)
Non-overlapping
Each DNA triplet and gene is separate from each other
Degenerate
The same amino acid can be coded for by more than one triplet
Genome
The complete set of genes (all) in a cell/organism
Proteome
The full range of proteins that a cell can make
Splicing
Removing of introns
Codon
Triplet of bases on mRNA that codes for a specific amino acid
Anticodon
Triplet of bases on tRNA that is complementary of codon on mRNA
Gene mutation
Change to base sequence of DNA during DNA replication
Substitution
Swapping one base for a different base
The polypeptide will differ in a single amino acid, sometimes it doesn’t have an affect
Deletion
One base is removed
Results in the entire amino acid sequence changing, polypeptide wont be able to function properly
Homologous pairs
One chromosome from each parent
Same gene but different alleles
Gamete
Haploid sex cells
Haploid (n)
A cell with a single set of unpaired chromosomes (one of each homologous pair)
Diploid (2n)
A cell with two complete sets of chromosomes (both homologous pair - one from each parent)
Fertilisation
Fusion of 2 haploid gametes from a zygote
Meiosis
Cell division to form gametes
Mitosis
Cell division for growth and repair
Crossing over
Different combination of alleles
Independent segregation
Different combination of chromosomes
Polypeptide
More than one amino acid in chain
Nucleotides
Monomers that make up DNA made up of an organic base, sugar and a phosphate
Chromosome
A thread like structure made of a protein and DNA by which hereditary information is physically passed from one generation to the next
Allele
Alternative forms of the same gene with different base sequences and therefore different codes
Genetic diversity
The number of different alleles of a gene in a population
Natural selection
Individuals of a population that are best suited to their environment survive ad reproduce more. (Beneficial alleles are more likely to be passed on)
Evolution
Change in allele frequency over time
Chromosome non-disjunction
When chromosomes don’t separate properly during meiosis 1 or meiosis 2
