Chapter 9 Lab Bio Chapter 12 Honors Bio

 Brainstorm : - define genetics - define heredity  Anticipatory Set:  How important is it to be able to find your own answers to questions you may face?  Does education and learning end with your high school or college years?  How do you plan to develop the skills to become a life long learner?

 The study of how characteristics are transmitted from parent to offspring

 The transmission of characteristics from parent to offspring

 Chromosome: structure within nucleus, made of DNA  Gene: unit of heredity found in DNA molecule (words)  Allele: symbols (letter) used to represent genes ex: T=tall, t=short  Dominant: trait/characteristic that are expressed – represented with capital letter  Recessive: trait/characteristic that may not be expressed (always lower case) ex: t=short

 Homozygous/pure: both alleles are alike ex: TT or tt  Heterozygous/hybrid: alleles differ ex: Tt  Genotype: genetic make up ex: pure )homozygous) tall, hybrid (hetero.) tall  Phenotype: what you see (physical appearance) ex: tall, short  Cross: symbolic of reproduction ____ X _____  P: parent generation  F1: first generation

 Do you think that we could make as many discoveries in science if we didn’t use animals? Explain…..

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 Austrian Monk  Studied garden pea plants (Pisum sativum)  1842 he entered the monastery in Austria  1851 enetered Univ. of Vienna to study science and mathematics (statistics)

 Observed 7 characteristics each in 2 contrasting traits:  Long  short stems  Axial  terminal (flower position)  Green  yellow (pod color)  Inflated  constricted (pod appearance)  Smooth  wrinkled (seed texture)  Yellow  green (seed color)  Purple  white (flower color)

 He controlled how pea plants were POLLINATED!!!  SELF POLLINATION=pollen is transferred from anthers (male) of a flower to stigma (female) of same flower or flower on the same plant  CROSS POLLINATION=involves flowers of 2 separate plants

 1. remove anthers from a flower  2. manually transfer the anther of a flower on one plant to stigma of a flower on another plant

 P 1 (cross) yellow x green  Law of Dominance  F 1 ALL GREEN  F 1 (cross) green x green  Law of Segregation  F 2 ¾ GREEN, ¼ YELLOW

 Mendel hypothesized that the trait appearing in the F 1 generation was controlled by a DOMINANT FACTOR because it masked, or dominated, the other factor for a specific characteristic.  RECESSIVE is the trait that did not appear in the F 1 generation but reappeared in the F 2 generation.

 A pair of factors (alleles) is segregated (or separated) during the formation of gametes  Each reproductive cell (gamete) receives only one factor of each pair.  Crossed two heterozygous green plants!

 He also crossed plants with 2 different characteristics  Ex: flower color & seed color  FACTORS FOR DIFFERENT CHARACTERISTICS ARE DISTRIBUTED TO GAMETES INDEPENDENTLY.  Ex: Pure tall yellow x pure short green  TTYY x ttyy

 A GENE is the segment of DNA on a chromosome that controls a particular trait.  Chromosomes are in pairs i.e.  Genes occur in pairs (each of several alternative forms of a gene is called an ALLELE  MENDEL’S FACTORS ARE NOW KNOW AS ALLELES!!!!!!

 CAPITAL = Dominant alleles  Lower case = recessive alleles  Example: G = green color (dom.)  g = Yellow pod color (rec.)  When gametes combine in fertilization offspring receive ONE ALLELE for a given trait from EACH PARENT!

 Helps us predict the likely outcome of offspring!!  1. genotype: genetic make-up, consists of alleles  Ex: P=purple, p=white  Pp = purple  PP = purple  White = pp

 2. Phenotype = appearance of an offspring (what you see)  Ex: purple flowers, white flowers, hair color

 3. Homozygous = when both alleles of a pair are alike  Ex: tt, TT, PP, pp  Homozygouse recessive = pp  Homozygouse dominant = PP

 4. Heterozygous = two alleles in a pair are different  Ex: Pp or Tt

 Law of Dominance  Law of Segregation  Test Cross  MENDEL’E RULES DO NOT APPLY TO :  Incomplete dominance  Multiple alleles  Codominmanmce  Polygenic inheritance  Pleiotyropy  Environmental influence

 Law of dominance  Law of segregation  Test cross  Incomplete dominance  Codominance  Independent assortment  Sex determination  Sex linkage  Multiple alleles