THE NECESSARY VOCABULARY & OTHER FACTS
GREGOR MENDEL – THE FATHER OF GENETICS AUSTRIAN MONK RESEARCHED HOW TRAITS ARE PASSED FROM GENERATION TO GENERATION BY CONDUCTING EXPERIMENTS WITH PEA PLANTS
THE STUDY OF HEREDITY
Seed Shape Flower Positio n Seed Coat Color Seed Color Pod Color Plant Heigh t Pod Shape Round Wrinkled Round Yellow Green Gray White Smooth Constricted Green Yellow Axial Terminal Tall Short YellowGraySmoothGreenAxialTall Section 11-1 Figure 11-3 Mendel’s Seven F 1 Crosses on Pea Plants Go to Section:
PLANTS, THAT IF ALLOWED TO SELF- POLLINATE, WILL PRODUCE OFFSPRING IDENTICAL TO THEMSELVES. THE BASIS OF MENDELIAN GENETICS WERE THE TRUE-BREEDING PLANTS
A SPECIFIC CHARACTERISTIC EXAMPLE: ◦ SEED COLOR ◦ PLANT HEIGHT
THE ORIGINAL PAIR OF ORGANISMS CROSSED;
(FIRST FILIAL) THE FIRST GENERATION THAT IS PRODUCED BY THE PARENT GENERATION
THE SECOND GENERATION PRODUCED BY CROSSES BETWEEN THE F 1 GENERATION
P Generation F 1 Generation F 2 Generation TallShortTall Short Section 11-1 Principles of Dominance Go to Section:
THE CHEMICAL FACTORS THAT DETERMINE TRAITS A REGION OF DNA THAT CONTROLS A HEREDITARY CHARACTERISTIC. A GENE CARRIES BIOLOGICAL INFORMATION IN A FORM THAT MUST BE COPIED AND TRANSMITTED FROM EACH CELL TO ALL OF THE NEW DAUGHTER CELLS. (MENDEL DID NOT KNOW WHAT GENES WERE – HE REFERRED TO THEM AS FACTORS)
THE DIFFERENT FORMS OF A GENE EXAMPLE: THE GENE FOR HEIGHT HAS TWO ALLELES ◦ TALL ALLELE ◦ SHORT ALLELE
AN ORGANISM WITH A RECESSIVE ALLELE FOR A PARTICULAR FORM OF A TRAIT WILL HAVE THAT FORM ONLY WHEN THE DOMINANT ALLELE FOR THE TRAIT IS NOT PRESENT. REPRESENTED BY LOWER-CASE LETTERS EX. tt = short
AN ORGANISM WITH A DOMINANT ALLELE FOR A PARTICULAR TRAIT WILL ALWAYS EXPRESS THAT TRAIT. ALWAYS REPRESENTED BY CAPITAL LETTERS EX. TT = TALL
SOME ALLELES ARE DOMINANT AND SOME ALLELES ARE RECESSIVE
FOR ANY PARTICULAR TRAIT, THE PAIR OF ALLELES OF EACH PARENT SEPARATE AND ONLY ONE ALLELE PASSES FROM EACH PARENT ON TO AN OFFSPRING
A DIAGRAM THAT DETERMINES THE GENE COMBINATIONS THAT CAN RESULT FROM A GENETIC CROSS.
Section 11-2 Tt X Tt Cross Go to Section:
ORGANISMS THAT HAVE TWO IDENTICAL ALLELES FOR A PARTICULAR TRAIT. HOMOZOYGOUS ORGANISMS ARE TRUE- BREEDING FOR A PARTICULAR TRAIT. EX. TT OR tt
ORGANISMS THAT HAVE TWO DIFFERENT ALLELES FOR A PARTICULAR TRAIT HETEROZYGOUS ORGANISMS ARE HYBRID FOR A PARTICULAR TRAIT. EX. Tt
THE PHYSICAL CHARACTERISTICS OF AN ORGANISM THAT ARE EXPRESSED. EXAMPLE: ◦ HEIGHT ◦ HAIR COLOR ◦ EYE COLOR ◦ SEED SHAPE ◦ SEED COLOR
THE RATIO OF THE POSSIBLE PHENOTYPES PRODUCED FROM A CROSS; EX: TWO TALL : TWO SHORT
THE GENETIC MAKEUP OF AN ORGANISM ALL OF THE GENES THAT ARE PRESENT IN AN ORGANISM EXAMPLE: ◦ TT; Tt; Rryy; RRYy;
THE RATIO OF THE POSSIBLE GENOTYPES FROM EACH CROSS; EX: 2 TT: 1Tt: 1tt
THE LIKELIHOOD THAT A PARTICULAR EVENT WILL OCCUR PROBABILITIES PREDICT THE AVERAGE OUTCOME OF A LARGE NUMBER OF EVENTS. PROBABILITY CANNOT PREDICT THE PRECISE OUTCOME OF AN INDIVIDUAL EVENT. THE PRINCIPLE OF PROBABILITY CAN BE USED TO PREDICT THE POSSIBLE OUTCOME OF GENETIC CROSSES.
EACH TRAIT HAS ONE PAIR OF TWO CONTRASTING CHARACTERISTICS EXAMPLE: ◦ TALL AND SHORT (Tt) ◦ GREEN AND YELLOW (Yy) ◦ Tt x tt
TWO-FACTOR CROSS EACH TRAIT HAS TWO PAIR OF TWO CONTRASTING TRAITS EXAMPLE: ◦ ROUND YELLOW PEAS (RRYY) ◦ WRINKLED GREEN PEAS (rryy) ◦ RRYY x rryy
Section 11-3 Figure Independent Assortment in Peas Go to Section:
EACH PAIR OF ALLELES SEGREGATES INTO GAMETES INDEPENDENTLY OF THE PAIR OF ALLELES FOR ANY OTHER GENE
States that diploid organisms inherit two genes per trait, and each gene segregates from the other during meiosis such that each gamete will receive only one gene per trait.
concluded that which is called the Gregor Mendel Law of Dominance Law of Segregation Pea plants “Factors” determine traits Some alleles are dominant, and some alleles are recessive Alleles are separated during gamete formation Section 11-3 Concept Map Go to Section: experimente d with