1 / 11

Mendelian Genetics

Mendelian Genetics. Chapter 10.2 (277). How Genetics Began. Mendel and Others Studied Garden-Pea Traits Gregor Mendel was an Austrian monk He was the first to apply mathematics to predict the way traits would be passed from one generation of pea plant to the other. Why peas?

oliver
Download Presentation

Mendelian Genetics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Mendelian Genetics Chapter 10.2 (277)

  2. How Genetics Began Mendel and Others Studied Garden-Pea Traits • Gregor Mendel was an Austrian monk • He was the first to apply mathematics to predict the way traits would be passed from one generation of pea plant to the other. • Why peas? • Has traits that are easy to tell apart (table 8-1) • Mating of garden peas can be easily controlled • Garden peas are small, grow easily and quickly, and produce many offspring

  3. The Inheritance of Traits Mendel Observed that Traits Are Expressed as Simple Ratios • Mendel’s first experiments were monohybrid crosses – a cross that involves one pair of contrasting traits (ex. Purple flowers crossed with white flowers) • Most of Mendel’s experiment followed these steps:

  4. The first two plants crossed were the P generation (parental generation) • He then cross pollinated two P generation plants that had contrasting traits and called the resulting plants the F1 generation (first filial generation) • He allowed the F1 generation self-pollinate and called the offspring the F2 generation (second filial generation)

  5. He was recording and analyzing quantitative data at every step… that’s what made him different!!!!

  6. Mendel’s Conclusions Mendel formed many hypotheses throughout his research: • For each inherited trait, an organisms has two copies of the gene • There are alternate versions of genes called alleles • When two different alleles occur together one may be expressed and the other may not. • Dominant allele (capital letter) = expressed • Recessive allele (lowercase letter) = not expressed

  7. Determine your dominant and recessive characteristics…

  8. Contemporary Genetics • Homozygous: both alleles are the same ex. TT or tt • Heterozygous: alleles are different ex. Tt • Genotype: the alleles combinations of an organism • Phenotype: physical appearance of an organism

  9. Mendel’s Ideas Gave Rise to the Laws of Heredity • Law of Segregation: States that two alleles for a certain trait segregate (separate) when gametes are formed (we now know this happens during meiosis.) • Law of Independent Assortment: This explained that when alleles of a gene pair separate during gamete formation, the assortment of alleles in the resulting gametes has nothing to do with other gene pairs. This allows for more variation

  10. Predicting Heredity • Punnett squares can predict the expected results in crosses • Probabilities can also predict the expected results of crosses

More Related