Unit 4 Stuff (genetics) Flashcards
factors
something within the pea plants controlled the characteristics he observed - Mendel called these controls factors
What did Mendel do
In one of his experiments, Mendel crossed a plant pure for green pods with one pure for yellow pods.
The resulting seeds produced an Fi generation with only green-podded plants - no yellow pods developed.
When Mendel allowed the Fiplants to self pollinate and planted the seeds, the F2generation plants resulted in & with green pods, and with yellows. pods.
He concluded that something within the pea plants controlled the characteristics he observed - he called these controls factors.
What did Mendel hypothesize
He hypothesized that each trait was inherited by means of a separate factor, and that there was a PAIR of factors controlling each trait.
Gene
A segment of DNA that contains coding for a polypeptide or protein; unit of hereditary information
Law of independent assortment
States that factors for different characteristics are distributed to gametes independently.
Ex: Green pea pod (dominant factor) could appear in a white-flowering plant (recessive factor)
Molecular genetics
study of the structure and function of chromosomes and genes.
Recessive and Dominant Traits
Dominant
referring to an allele that masks the presence of another allele for the same
characteristic, most common in population
Ex: green pods
Recessive and Dominant Traits
Recessive
referring to an allele that is masked by the presence of another allele for the same characteristic. (It was the trait that didn’t appear in the Figen but reappeared in the F gen)
Ex: yellow pods
Law of Segregation
When 2 gametes combine during fertilization, the offspring have two factors controlling a specific trait.
States that a pair of factors is segregated, or separated, during the formation of gametes (reproductive cell).
What are Mendel factors now called
Alleles
Capital and lowercase letters meaning
Capital letters = dominant allele
Lowercase letters = recessive dle but
Genotype:
genetic makeup of an organism, consists of alleles that the organism inherits from its parents (the letters)
Ex) If purple is dominant, so either PP or Pp would give a purple flower (P is dominant, masks recessive) and pp would give a white flower. PP, Pp and pp are the genotypes.
Phenotype:
Appearance of an organism as a result of its genotype.
Ex: PP, Pp = purple flower
pp = white flower
