BSC2011_SlideSet7_Unit2

BSC2011_SlideSet7_Unit2 - Next up in UNIT II: Patterns of...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Next up in UNIT II: Patterns of Inheritance How are genes and the traits for which they code passed along from parents to offspring? Father and son sisters brothers twins Family Mom and offspring SLIDE SET VIa Summer 11 Outline I. Mendel - A New Theory of Inheritance A. Who was Mendel? B. What did Mendel know? C. Plant breeding II. Mendel's work A. Monohybrid cross B. Interpretation in modern terms C. Quantitative results D. The dihybrid cross E. Summary of Mendel's Rules III. Probability Theory and Patterns of Inheritance A. Definitions B. Rules for probability C. Application to the dihybrid cross The Homunculus (Preformationism) vs. Pangenesis (Charles Darwin) How are traits pased on from parents to offspring? vs. blending inheritance Gregor Mendel (1822-1884)- an Austrian monk Common pea plant ( Pisum sativum ) http://anthro.palomar.edu/mendel/mendel_1.htm Why was he smart to use pea plants to study inheritance? Fig. 14.2 How controlled plant breeding is accomplished. Flowers hold a plants reproductive organs:- male organs are the STAMENS (make pollen)- female organ is the OVARY at the base of the sticky pistil REASONS FOR MENDELS SUCCESS- studied several different plant characteristics (or traits) (Table 14.1)- studied either-or traits that each had 2 distinct versions (alleles) (e.g. white flowers or purple flowers)- started simple: by studying one trait at a time 4. Made sure his starting plants were true breeding i.e., when self-fertilized, ONLY the same parental trait showed up in offspring generation after generation) 1. Used an organism (pea plant) that:- can both self- and cross- fertilize- produces MANY offspring (= seeds)- has a relatively short generation time (life cycle) 2. Subjected data to quantitative analysis 3. Used an organized, systematic (i.e., scientific) approach: See Table 14.1 seven of Mendels plant traits Fig 14.3 Mendels series of crosses: a monohybrid cross 705 purple 224 white Mendel saw an approximate 3:1 ratio among F2 offspring Mendel self- fertilized the F1 plants to generate the F2 F1= first filial generation (offspring) *100% purple (where did the white flower info go?) Mendel found the same pattern for all seven characteristics he studied: 1. Only one of two possible forms for a trait showed up in the first generation (F1) when the parents were true breeding for 2 different forms of a trait. 2. The form of the trait not seen in the first generation re-appeared in the second generation (F2), and always in a 3:1 ratio . Mendels explanation for his observed results: 1. Each characteristic (trait) is controlled by a separate factor (= a gene ) and there are 2 variants or forms (= alleles) for each gene in each plant....
View Full Document

Page1 / 40

BSC2011_SlideSet7_Unit2 - Next up in UNIT II: Patterns of...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online