Inheritance Flashcards
Mendelian inheritance
Gregor Mendel put together 2 principles relating to inheritance. 1)Various hereditary characteristics controlled by factors (genes) occurring in pairs and (2) during the formation of the gamete, the pairs of factors separate, each gamete receives only one set of factors, with the other set going to another gamete, these entire and allow for diff combo of genes
Mendels experiments
Breeding experiments with garden peas and studied 7 pairs of contrasting characteristics is which alternatives were easily identifiable
how he did it
Made sure plants were pure breeding for the characteristic he wanted to stud, pure breeding plants are those that produce the same characteristics in each succeeding generation when bred among themselves. He cross-bred plants with contrasting characteristics
When cross-breeding he found that
the offspring (progeny) resembled only one of the parents, offspring were hybrid because they have gen info for green seed colour and yellow. Mendel called the characteristic shown by hybrid as dominant as the masked other (recessive)
what happened when hybrids self pollinate
second gen was produced in which the characteristics reappeared in the ratio of 3 to 1. He concluded that hereditary factors were unchanged as they passed from one gen to the next and each pea had 2 hereditary factors for each characteristic and during gamete formation, they were segregated or separated with each gamete containing one gene for each trait
principle of segregation
the alleles for a trait are separated during of gametes
gene
The factor determining an inherited characteristic, in chromosome
allele
alt form of gene
dominant
An allele that masks the affect of another
recessive
the allele that is masked by the alt , dom allele
homozygous
Where an individual has the same allele for particular characteristics
heterozygous
An individual posses different alleles for a particular characteristic
phenotype
The physical appearance of an individual as determined by the expression of alleles for that characteristic
genotype
The genetic makeup of an individual is determined by alleles for characteristics being considered
punnet squares
used to model a cross and calc the probability of geno and phenotype of an individual. but not good to look at phenotypes produced in a family