topic 1 Flashcards
whats a function of the non-conding dna in the genome
they regulate transcription
genome
total genetic material present in an organism
what is a genome made of
made up of genes (coding regions) and other DNA sequences that do not code for a protein (non-coding regions)
whats the repeated strand in a dna
nucleotide - sugar base phosphate
whats a dna nucleotide made of
deoxyribose sugar, phosphate, base
what carbon does the base attach to
carbon 1
whats the backbone of a dna made of
the phosphate of one nucleotide and the carbon 3 of another , joined by strong chemical bonds
what holds the bases together
weak hydrogen bonds
what is needed for the leading strand during pcr
dna polymerase , primer
what does a lagging strand need during pcr and why
needs primer, its a short strand of nucleotides to start the dna replication
needs dna polymerase to add dna nucleotides
ligase is needed to put the fragments together
how does PCR happen
- heated to 95, hydrogen bonds break, dna unzips
- cooled to 55 allows primers to bind to their specific target sequences at the 3’ end
- heaed to 75, allows the heat tolerant dna polymerase to replicate the original dna
what is gene expression
is the activation of certain genes in a cell to produce a particular proteins, only a fraction of the genes in a cell are expressed
whats an rna made of
single stranded
made of nucleotide
ribose sugar, phosphate, base
mRNA
it carries a copy of the DNA code from the nucleus to ribosome
what r the rna bases
uracil-adenine
cytosine - guanine
tRNA
found in cytoplasm
binds to specific amino acids and transports them to ribosome
rRNA
forms a complex with protein molecules to make the ribosome
what happens during transcription
-rna polymerase moves along and unwinds double helix
rna polymerase synthesises a primary transcript of mrna from rna nucleotides by complementary base pairing
they pair up
and rna splicing occurs
codon
a triplet of three bases on mRNA each codes for a specific amino acid
what happens in translation
begins at mRNA start and stop codon
tRNA brings specific amino acids
the tRNA anti codons bind by complementary base pairing
peptide bonds join amino acid together
tRNA leaves
alternative rna splicing
happens when a different mature mRNA transcript is produced by the same primary transcript depending on which exons r retained
polypeptide structure
amino acids bonded by peptide bonds
three dimensial shape
held by hydrogen bonds
cellular differentiation
the process by which a cell expresses certain genes to produce proteins characteristics for that type of cell.
this allows a cell to carry out specialised functions
meristem cells
unspecialised cells in plants
embroyonic stem cells
pluripotent
tissue stem cells
multipotent can only differentiate into a cell related to tissue/muscle
mutations definition
mutations are changes to the dna
they arise spontaneously and at random but occur rarely
what is substitution mutation
single nucleotide substitution which can bring about only a minor change
what are the three types of substitution mutations
missense - little affect
nonsense - amino acids becomes into a stop codon, causes it to form a shorter polypeptide chain
splice site - results in some introns being retained or some exons been taken out
insertion definition
an extra nucleotide is added into the sequence
this alters all the codons
deletion definition
a nucleotide is removed from the sequence this alters al the codons
what mutation is classified as a frame-shift mutations
insertion and deletion as it alters all the amino acids from the mutation and onwards
what are the 4 types of chromosome mutations
involves the chromosome structure being altered
deletion
duplication
translocation
inversion
what is deletion chromosome structure mutation
a section of chromosome is removed
what is duplication chromosome structure mutation
a section of a chromosome is added from its homologous partner
what is translocation chromosome structure mutation
a section of chromosome is added from its non homologous partner
what is inversion chromosome structure mutation
a section of chromosome is reversed within itself
what is evolution
evolution is the change that occurs in organisms over generations as a result of genomic variation.
these variations take the form of changes in the frequencies of certain genetic sequences
vertical inheritance
genes are transferred from parent to offspring as a result of sexual or a sexual reproduction
horizontal inheritance
genes are transferred between individuals in the same generations
prokaryotic can transfer genetic materical (plasmids) from one cell to another horizontally
natural selection
is the non-random increase in frequency of DNA sequences that increase survival and the non-random reduction in deleterious (harmful) sequences
what are the types of selections that can occur for a quantitative trait
stabilising selection
directional selection
disruptive selection
whats a quantitative trait
a quantitative trait is polygenic, it is controlled by many genes working together
species definition
is a group of organisms that are able to interbreed with one another to produce fertile offspring
speciation
is the formation of a new species bought about by evolution as a result of isolation, mutation and selection
what is allopatric speciation
population becomes separate by a geographical barrier
what is a sympatric speciation
when 2 populations live in the same environment but become isolation due to behavioural or ecological barriers
genomic sequencing
is the sequence of nucleotide bases can be determined for an individual and entire genomes
bioinformatics
are computer programs that can be used to identify base sequences by looking for a sequences and similar to known genes
phylogenetics
is the study of evolutionary history and relationships
molecular clocks
molecular clocks are used to show when species diverged during evolution
what are the three domains of life
bacteria
archaea
eukaryotes (fungi plants n animals)
pharmacogenetics
is the use of genome information in the choice of drugs it could lead to personalised medication
suggest how a change in the sequence
of bases in DNA transcribed to rRNA in the mutated cultures resulted in a
decrease in protein synthesis.
Change in the sequence may change
the structure/function/shape of the
ribosome
Translation can no longer occur
A molecular clock was used to estimate the dates of the divergence of
each species.
Give one example of the type of data required to generate a molecular
clock.
-mutation rate
-dna sequence data
-fossils
species
is a group of organism that can produce off spring
when comparing genomic sequence data, bioinformatics is the use of
computer analysis, and statistical anaylsis
