pedigrees and inheritance Flashcards
genetics
the study of inheritance
(genes, DNA, chromosomes)
genes
units of code for certain traits
heredity
passing of traits from parents to offspring
mRNA
ACTG ACTG ACTG
“central dogma” of genetics
creates a specific mRNA and proteins depending on the pair
homologous chromosome
can carry 2 different versions of the same gene
gametes reflect…
the genetic information contributed by both parents
types of traits
species traits and individual traits
species traits
all members of the same species have certain genes
example- the ability to walk
individual traits
genes that make you different from others
example - eye color, hair color, taco tongue
gregor mendal
the father of genetics *1865
-experimented with pea plants, and the patterns in genetics
pollination process
stamen produces pollen, which is transfered to the pistil where egg is produced and fertilizes producing a seed
stamen
male reproductive part of the plant
-produces pollen
pistil
female reproductive part of the plant
-produces the egg, and stores fertilized seed momentarily
self pollination
plant transfers pollen to it’s own pistil
-offspring is genetically identical to parent
cross pollination
pollen is transferred from one plant to another
-offspring may look different from parent
parental generation
the intial breeding, parents
first filial generation
-creates hybrid
intial mixing of the parents genetic traits
major thing mendal discovered from crossing plants
evidence of dominat traits
categories mendal observed
-seed form
-seed color
-pod form
-pod color
-flower position
-seed coat color
-stem length
captial letters mean
dominate trait
lower case letters indicate
recessive trait
mendals hypothesis
- inherited traits are controlled by genes, which occurs in pairs
- one gene may be more dominate or recessive
- law of segregation
- law of independant assortmnent
heterozygote
Gg
-different traits
homozygote
gg or GG
-same traits
law of segregation
based on random chance heterozygotes produce (eventually) equal numbers of gametes having the two different allels
law of independant assortment
factors form a pair that is seperated/distributed randomly, and not based on other seperations or distributions
-any sort of combination
genotype
the actual genes present in an organism
(TT, tt)
phenotype
the physical expression of a gene
(tall/short)
homo
same
hetero
different
allels
are different forms of a gene that have different effects on a trait
example- T and t are both allels for height
punnett squares
help to determine the probability of an offspring having a certain genotype or phenotype
-based on parents genotype
monohybrid crosses
single trait genetic cross with ONE PAIR of contrasting traits
expression of genotype percentage
*number % *Rr
test cross
cross on an organism of an unknown genotype with a homozygous recessive individual
-resulting ration helps to determine genotypes of the unknown
incomplete dominance
hybrid phenotype is a mix (shows as imbetween) of the pure breeding/phenotypes
true breeding strain
always will get the same thing you started with
codominance
both alleles are expressed in an individual
example - blood types A, B, AB*
AB-codominance in antigens
multiple alleles
more than two allels exist for a trait
example - A blood type can be AA or AO
carrier
hybrid, contains usually a disease that is recessive
how many alleles can fit in a gene
two
selective breeding
crossing desired traits to produce offspring with certain characteristics
hybridization
blending different traits to produce new offspring
dihybrid crosses
two independant trait crosses
-makes gametes FOIL
-need one allele from each trait
two rules of probability
1- each event is individual, doesn’t influence other outcomes
2- the chance of one event occuring simultaneously
polygenic traits
different genes can interact to control the phenotype expression of a single characyeristic
example - skin tone, eye color
epistasis
interaction between two genes that modfiy the phenotype expression of all other genes
example - albanism
complimentary interaction
two gene pairs prpduce a trait that neither can do by themselves
pleiotopic genes
one gene affercts many characteristics
example - marfan syndrome (affects physical)
lethal alleles
gene or allele that leads to death of an individual
-can be dominant or recessive
example - huntingtons disease`
lethal alleles
gene or allele that leads to death of an individual
-can be dominant or recessive
example - huntingtons disease
huntingtons disease
defective protein in the brain
walter sutton and theodore boveri
both noted the mendalian laws were applicable to chromosomes at a cellular level
thomas hunt morgan
studied the fruit flie
-discovered sex linked genes
autosomal dominant
females and males equally likely to have trait
-doesnt skip generations
autosomal recessive
males and females equally likely to have trait
-skip generations
x linked dominant
all daughters of a male who has the trasit will also have the trait
-zero male to male
x linked recessive
all daughters of a male who has the trait are carries
-more common in males than females
mutation
change in the genetic code
gene point mutation
base in DNA has changed
-like a genetic typo
chromosomal mutation
caused by nondisjunction crossing over or lack of some/all of a chromosome
somatic
affects body cells
-new trait may appear
germline
affects reproductive cells
-is passed onto an offspring
causes of mutation
chemicals, radiation, temperature, replication errors
enviromental influence
traits can be altered or changed due to enviromental effects
gene action
genes interact with the enviroment
-blend between nature and nurture
fraternal twins
develope from 2 different eggs fertilized by 2 different sperms
identical twins
develope from a single fertilized egg that splits into two cells
dominant rhesus factor
positive
what blood type is codominant
A/B
what blood type is dominant over O
A/B
what would happen if both X’s were active in females
they’d produce twice as much protein in comparasion to males
-so one chromosome is randomly inactivated in every single cell
example - speckled cats
friedrich miescher
discovered DNA in 1989, named it NUKLEIN
walter fleming
introduced the term chromatin, 1879
-nuklein and chromatin are the same thing
by the 1900s what was understood…
chromatin consisted of DNA and proteins
-BUT could not agree which was the actual genetic material
PAT levene
thought DNA was too simple (believed protein to be genetic material)
-life is too complex to be made up of only four
tetranucleotide hypothesis
the digram of DNA
why did PAT levene think protein was the genetic material
-protein was more diverse (amino acids) and combinations leads to more complex folding patterns
hereditary molecules must be able too
- control protein and enzyme production
- sekf replicate accuratley
- change/adapt
- found in the nucleus
griffiths experiment concluded
that the non virulent bacteria somehow turned virulent when combined with virulent bacteria, due to denaturing
