Unformatted text preview: ANNOUNCEMENTS - Monday, February 22nd • Results of Midterm II: Mean: 114 +/- 19 (last time 119 +/- 18) High Score: 156.5 Low Score: 69.5 Grade Estimates: A 130-150 B 112-129 C 93-111 D 74-92 • Exams returned after class tonight. • Wednesday will feature “The Double Helix”. Movie about Watson and Crick’s race for the structure of DNA. Exam questions will cover the movie. 97 Minutes!! Asexual vs. Sexual Reproduction
Figure 13.1 Asexual reproduction Mendelian Genetics One parent produces genetically identical offspring by mitosis Parent Bud 0.5 mm Sexual reproduction Chapter 14 Two parents give rise to offspring with unique combinations of genes Offspring inherit a combination of parental traits Heredity
transmission of traits from one generation to the next What genetic principles account for the transmission of traits from parents to offspring? Variation
offspring differ from parents and siblings X The “blending” hypothesis of inheritance
- Genetic material from parents mix in each generation No Yes The “particulate” hypothesis of inheritance Genetics scientific study of heredity and hereditary variation
- Parents pass on discrete heritable units, genes Gregor Mendel, the father of genetics
Documented a “particulate” mechanism of inheritance through his experiments with garden peas 1857- Experimental discovery of inheritance mechanisms Mendel asked questions:
What are the causes of variation in plants? Mendel devised carefully-planned experiments:
Controlled breeding between varieties of garden peas and mathematical analysis of offspring Mendel interpreted his results:
Discovered two Laws of inheritance!
Figure 14.1 Mendel’s Two Laws of Inheritance 1. Law of Segregation 2. Law of Independent Assortment Mendel’s Experimental, Quantitative Approach Mendel’s good decision to work with peas (or why he was supremely lucky):
• • • • • “true-breeding” varieties controlled matings (parent crosses) can easily track multiple generations “either-or” characters large sample size, for statistics Genetic Vocabulary How to Cross (Pollinate) Pea Plants
1 Removed stamens from purple flower
2 Transferred sperm- METHOD:
1. Transfer pollen from white flower to purple flowers Pollinated carpel makes pod Character
a heritable feature,
such as flower color
Parental generation (P) bearing pollen from stamens of white flower to eggbearing carpel of purple flower 3 Pollinated carpel Stamens Carpel (male) (female) Trait
a variant of a character,
such as p...
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This note was uploaded on 04/03/2010 for the course BIOLOGY BILD 1 taught by Professor Traver during the Winter '10 term at UCSD.
- Winter '10