genetic methods Flashcards
what is dominant allele
an allele that is expressed in the phenotype, even when only one copy is present
what is recessive allele
an allele that is only expressed when two copies are present in the genotype
what is mendelian inheritance
two parents with dominant gene can have a child with recessive gene
what are the 2 fundamental laws of mendelian inheritance
- segregation - traits are either dominant or recessive
- independence - varieties of each trait sort independently of each other
what is DNA
- genetic code
- can be found in the nucleus of every cell of an organism
- composed of two chains of nucleotides that coil around each other to form a double helix
what is translation in DNA
strands are unzipped and read by RNA molecules to produce protein strands
what are chromatids
long strands of DNA in nucleus, tangled together
what happens during mitosis
- chromatids undergo condensation - they coil tight to form a chromosome
what chromosomes do typical humans have
46
- all pairs are XX aside from final pair which may vary
- females have XX and males XY
how many genes do humans process
between 20,000 to 25,000
what is a pleiotropic trait
phenotype traits programmed by a single gene
what is a polygenic trait
- influenced by a combination of genes
what are x-linked conditions
some recessive trats are more prevalently expressed in males when compared to females because they may not have a dominant allele on their y chromosome
- examples
- colour blindness
- turner syndrome
- klinefelter syndrome
- fragile x syndrome
what is an example of sporadic mutations
down syndrome
williams syndrome
what is an example of polygenic traits
schizophrenia
what are genomic studies
- inspect genome of specific group
- identify allele commonalities
- study families
what are targeted mutations
- mutated lab produced genes inserted into chromosomes
- can fail to produce function
- can produce new or different proteins
what does CRISPR stand for
- clustered, regularly, interspaced, short, palindromic, repeats
what does CRISPR allow
allows us to directly edit our own genome
