Genetics Flashcards
define gene
a heritable factor that controls a specific characteristic
what is a plasmid
small circular piece of DNA in the cytoplasm
homologous chromosome
carry the same sequence of genes but not necessarily the same allele
which chromosome determine gender
sex chromosomes
what chromosomes do not determine the sex of an organism
autosomes
what is a locus
specific spot on a chromosome that is occupied by that gene
how are new alleles formed
mutations
define genome
the whole of the genetic information of an organism
define genome size
total length of dna in an organism including all the non-coding sequences
what did the human genome project do
determined the entire base sequence of all the human chromosomes
what were the outcomes of the human genome project
- imporved knowledge of how human genes function
- improved diagnosis of genetic diseases
- increased potential for gene therapy
- increased potential to design drug to combat genetic malfunctions
what causes sickle cell anaemia
a base subtitution mutation - mutation in one of the two haemoglobin genes
what causes sickle cell anaemia
a base subtitution mutation - mutation in one of the two haemoglobin genes
- amino acid glutamic acid is replaced by valine
what was cairns technique used for
measuring DNA molecules
what are mutagens
chemicals that cause gene mutations
what is a tendem repeat
short sequence of bases in the DNA that are repeated
how are segments of tandem repeats extracted
using restriction endonuclease enzymes
outline PCR
- polymerase chain reaction
- copies and amplifies minute quantities of DNA
- only specific parts of the DNA are amplified
- this is done by adding specific primers to the complementary regions of DNA
- DNA can be used for profiling using gel electrophoresis
what are the 2 stages of PCR
- dna heated to seperate strands and primers are added
- dna taq polymerase and dNTPs added to build new strand
outline gel electrophoresis
-PCR is used to amplify the amount of DNA
-the DNA is cut into fragments using restriction endonucleases
the fragments have a small negative charge due to phosphate group
they will move through a gel towards a positive electrode
the smaller the fragment the further it will move
the DNA bands are stained
used for DNA profiling
outline DNA profiling
PCR
Gel electrophoresis
Bands of DNA are compared
uses of DNA profiling
paternity test
forensic investigations
family relationships for immigrants
what are the key requirements for the production of insulin using gene transfer
- the insulin gene
- a plasmid
- a host bacterium
- four enzymes: reverse transcriptase, DNA polymerase, a restriction endonuclease, DNA ligase
process of production of human insluin using gene transfer
- remove plasmid from bacterium
- cut with specific restriction endonuclease to produce sticky ends
- add insuling gene, join loose ends with ligase
- insert into bacterium
