Mendel's Monohybrid Experiments PDF

Mendel’s Monohybrid Experiments Why Mendel Chose Pea Plants Why Mendel Chose Pea Plants All of the data that Mendel collected, and the laws and principles that he developed were based on experiments with the common pea plant, Pisum sativum. This was Mendel’s subject of choice for several...

Mendel’s Monohybrid Experiments Why Mendel Chose Pea Plants Why Mendel Chose Pea Plants All of the data that Mendel collected, and the laws and principles that he developed were based on experiments with the common pea plant, Pisum sativum. This was Mendel’s subject of choice for several reasons: Why Mendel Chose Pea Plants All of the data that Mendel collected, and the laws and principles that he developed were based on experiments with the common pea plant, Pisum sativum. This was Mendel’s subject of choice for several reasons: ○ It was readily available to him. Why Mendel Chose Pea Plants All of the data that Mendel collected, and the laws and principles that he developed were based on experiments with the common pea plant, Pisum sativum. This was Mendel’s subject of choice for several reasons: ○ It was readily available to him. ○ It had several characteristics that displayed distinct, contrasting traits. Why Mendel Chose Pea Plants All of the data that Mendel collected, and the laws and principles that he developed were based on experiments with the common pea plant, Pisum sativum. This was Mendel’s subject of choice for several reasons: ○ It was readily available to him. ○ It had several characteristics that displayed distinct, contrasting traits. ○ It was fast-growing and generated large numbers of offspring. Why Mendel Chose Pea Plants All of the data that Mendel collected, and the laws and principles that he developed were based on experiments with the common pea plant, Pisum sativum. This was Mendel’s subject of choice for several reasons: ○ It was readily available to him. ○ It had several characteristics that displayed distinct, contrasting traits. ○ It was fast-growing and generated large numbers of offspring. ○ Its reproduction could be controlled. Mendelian Terminology Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). ○ Alleles = the different forms of a factor for a trait. Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). ○ Alleles = the different forms of a factor for a trait. ○ Dominant allele = a factor that will always be expressed if present. Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). ○ Alleles = the different forms of a factor for a trait. ○ Dominant allele = a factor that will always be expressed if present. ○ Recessive allele = an allele that will be masked by a dominant allele. Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). ○ Alleles = the different forms of a factor for a trait. ○ Dominant allele = a factor that will always be expressed if present. ○ Recessive allele = an allele that will be masked by a dominant allele. ○ Homozygous = to possess identical alleles for a trait. Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). ○ Alleles = the different forms of a factor for a trait. ○ Dominant allele = a factor that will always be expressed if present. ○ Recessive allele = an allele that will be masked by a dominant allele. ○ Homozygous = to possess identical alleles for a trait. ○ Heterozygous = to possess one dominant and one recessive allele for a trait. Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). ○ Alleles = the different forms of a factor for a trait. ○ Dominant allele = a factor that will always be expressed if present. ○ Recessive allele = an allele that will be masked by a dominant allele. ○ Homozygous = to possess identical alleles for a trait. ○ Heterozygous = to possess one dominant and one recessive allele for a trait. ○ Genotype = the pair of alleles possessed by an individual. Mendelian Terminology Mendel’s experiments, and his interpretation of them, provided geneticists with a vocabulary that is still largely used today. ○ Factor = a heritable unit that is passed from parents to offspring (i.e. genes). ○ Alleles = the different forms of a factor for a trait. ○ Dominant allele = a factor that will always be expressed if present. ○ Recessive allele = an allele that will be masked by a dominant allele. ○ Homozygous = to possess identical alleles for a trait. ○ Heterozygous = to possess one dominant and one recessive allele for a trait. ○ Genotype = the pair of alleles possessed by an individual. ○ Phenotype = the physical trait displayed by an individual. The Process of True-Breeding The Process of True-Breeding Mendel began all of his experiments by repeatedly breeding pea plants with the identical trait until all of the offspring display this same parental trait. The Process of True-Breeding Mendel began all of his experiments by repeatedly breeding pea plants with the identical trait until all of the offspring display this same parental trait. The Process of True-Breeding Mendel began all of his experiments by repeatedly breeding pea plants with the identical trait until all of the offspring display this same parental trait. The Process of True-Breeding Mendel began all of his experiments by repeatedly breeding pea plants with the identical trait until all of the offspring display this same parental trait. The Process of True-Breeding Mendel began all of his experiments by repeatedly breeding pea plants with the identical trait until all of the offspring display this same parental trait. The Process of True-Breeding Mendel began all of his experiments by repeatedly breeding pea plants with the identical trait until all of the offspring display this same parental trait. This process of true-breeding ensured that all of the individuals that he entered into his crosses had two identical alleles - in other words, were of a homozygous genotype. The Process of True-Breeding Mendel began all of his experiments by repeatedly breeding pea plants with the identical trait until all of the offspring display this same parental trait. This process of true-breeding ensured that all of the individuals that he entered into his crosses had two identical alleles - in other words, were of a homozygous genotype. Not surprisingly, this was a very quick process with plants that displayed the recessive phenotype, but took many generations with dominant-displaying plants. The F Generation 1 The F Generation 1 Mendel’s then crossed two individuals with contrasting traits - i.e. one individual with a dominant phenotype and one individual with a recessive phenotype. The F Generation 1 Mendel’s then crossed two individuals with contrasting traits - i.e. one individual with a dominant phenotype and one individual with a recessive phenotype. Invariably, 100% of the offspring would display the dominant trait - he termed this the F1 generation. The F Generation 2 The F Generation 2 Next Mendel generated an F2 generation by crossing two of the F1 generation individuals. The F Generation 2 Next Mendel generated an F2 generation by crossing two of the F1 generation individuals. Regardless of the characteristic being considered, Mendel always observed the reemergence of the recessive trait in roughly one quarter of the offspring. Mendel’s Conclusions Mendel’s Conclusions Parents possess a pair of factors for any given characteristic. Mendel’s Conclusions Parents possess a pair of factors for any given characteristic. During the production of gametes, the factors in a parent organism are separated such that only factor resides within each gamete - the law of segregation. Mendel’s Conclusions Parents possess a pair of factors for any given characteristic. During the production of gametes, the factors in a parent organism are separated such that only factor resides within each gamete - the law of segregation. One of the factors in an individual with differing factors (i.e. a heterozygote) will always mask the effect of the other factor - the principle of dominance. Punnett Squares Punnett Squares Mendel neither developed, nor used Punnett squares, but they are a simple way of summarizing the transmission of alleles and traits from parents to offspring. Punnett Squares Mendel neither developed, nor used Punnett squares, but they are a simple way of summarizing the x transmission of alleles and traits from parents to offspring. A complete Punnett square, specifically, indicates: Punnett Squares Mendel neither developed, nor used Punnett squares, but they are a simple way of summarizing the x transmission of alleles and traits from parents to offspring. A complete Punnett square, specifically, indicates: ○ The genotypes of the parents. Punnett Squares Mendel neither developed, nor used Punnett squares, but they are a simple way of summarizing the x transmission of alleles and traits from parents to offspring. A complete Punnett square, specifically, indicates: ○ The genotypes of the parents. ○ The possible gametes produced by the parents. Punnett Squares Mendel neither developed, nor used Punnett squares, but they are a simple way of summarizing the transmission of alleles and traits from parents to offspring. A complete Punnett square, specifically, indicates: ○ The genotypes of the parents. ○ The possible gametes produced by the parents. Punnett Squares Mendel neither developed, nor used Punnett squares, but they are a simple way of summarizing the transmission of alleles and traits from parents to offspring. A complete Punnett square, specifically, indicates: PP Pp ○ The genotypes of the parents. ○ The possible gametes produced by the parents. Pp pp ○ The genotypes of any potential offspring. Punnett Squares The interpretation of the Punnett square entails reporting: PP Pp Pp pp Punnett Squares The interpretation of the Punnett square entails reporting: ○ The phenotype ratio expected in the offspring. Punnett Squares The interpretation of the Punnett square entails reporting: ○ The phenotype ratio expected in the offspring. 3 purple : 1 white Punnett Squares The interpretation of the Punnett square entails reporting: ○ The phenotype ratio expected in the offspring. 3 purple : 1 white ○ The genotype ratio expected in the offspring. Punnett Squares The interpretation of the Punnett square entails reporting: ○ The phenotype ratio expected in the offspring. 3 purple : 1 white ○ The genotype ratio expected in the offspring. 1 PP : 2Pp : 1 pp Punnett Squares The interpretation of the Punnett square entails reporting: ○ The phenotype ratio expected in the offspring. 3 purple : 1 white ○ The genotype ratio expected in the offspring. 1 PP : 2Pp : 1 pp (1 H.D. : 2 He : 1 H.R.)