MENDELIAN GENETICS Flashcards
PART 1 AND 2
- Gregor Johann Mendel
- 1866
- major postulates of transmission genetics
- garden pea (Pisum sativum)
- discrete units of inheritance exist and predicted their behavior during the formation of gametes (elementen)
- Mendel’s postulates were accepted as the basis for the study of what is known as transmission genetics.
MENDELIAN GENETICS
- easy to grow and hybridize
artificially - self-fertilizing in nature
- seven visible features (unit characters), each represented by two contrasting forms, or traits
- Character: stem height: traits: tall and dwarf
- He selected six other visibly contrasting pairs of traits involving seed shape and color, pod shape and color, and pod and flower arrangement.
GARDEN PEA
Mendel’s simplest crosses involved only one pair of contrasting traits from two parent strains, each exhibiting one of the two contrasting forms of the character under study
MONOHYBRID CROSS
Offspring of self-fertilizing individuals
SELFING
MENDELIANS’ FIRST THREE POSTULATES:
Genetic characters are controlled by unit factors that exist in pairs in individual organisms.
UNIT FACTORS IN PAIRS
MENDELIANS’ FIRST THREE POSTULATES:
When two unlike unit factors responsible for a single character are present in a single individual, one unit factor is dominant to the other, which is said to be recessive.
DOMINANCE/RECESSIVENESS
MENDELIANS’ FIRST THREE POSTULATES:
During the formation of gametes, the paired unit factors separate or segregate randomly so that each gamete receives one or the other with equal likelihood.
SEGREGATION
MODERN GENETIC TERMINOLOGY:
The physical appearance of a trait is the ____ of the individual.
PHENOTYPE
MODERN GENETIC TERMINOLOGY:
Mendel’s unit factors represent units of inheritance called ___ by modern geneticists.
GENES
MODERN GENETIC TERMINOLOGY:
The phenotype is determined by alternative forms of a single gene called
ALLELES
MODERN GENETIC TERMINOLOGY:
When alleles are written in pairs to represent the two unit factors (DD, Dd, or dd), these symbols are called the ____.
GENOTYPE
MODERN GENETIC TERMINOLOGY:
When both alleles are the same (DD or dd), the individual is _____ or a ______.
HOMOZYGOUS OR A HOMOZYGOTE
MODERN GENETIC TERMINOLOGY:
When the alleles are different (Dd), we use the term ____ or a ____.
HETEROZYGOUS OR A HETEROZYGOTE
TERMINOLOGIES:
The genetic constitution of a individual (PP, Pp, pp)
GENOTYPE
TERMINOLOGIES:
The outward appearance of an individual (purple, white)
PHENOTYPE