Download presentation
Presentation is loading. Please wait.
Published byPhilippa Townsend Modified over 6 years ago
1
Title: Biology 1/25/07 Objectives: Class Topics
11/11/2018 Title: Biology 1/25/07 Objectives: To assess learning about genetic variation due to meiosis and about gametogenesis. Class Topics Hand in W.S. 8.1 before the bell rings please Review Chapter 7 Test Chapter 8 – Mendelian Genetics Terms Mendel’s research Mendel’s laws "It has become fashionable in science education to mold K-12 students around an idee fixe of a modern scientist; formulating hypotheses, observing measuring, and discovering through hands-on investigations. What has been left unsaid is that real scientists don't actually spend very much of their day 'observing' and 'measuring.' They read! Reading for understanding of content is the core process skill of science, and there is no substitute for practice at an early age Dr. Stan Metzenberg, "Reading: The Most Important Science Process Skill" Sunday, November 11, :35 AM
2
Class Assignments Read 161-165 1/25/07 W.S. 8.1 (DR/Quiz) 1/25/07
11/11/2018 Class Assignments What By When Read /25/07 W.S. 8.1 (DR/Quiz) 1/25/07 Read /29/07 W.S. “The Puzzle of Heredity” 1/29/07 Due this class period Due next class period Due in the future
3
11/11/2018 Grade Sheet 2A – p. 157 (5 pts.)
4
Chapter 7 Test Review Absolutely no talking
11/11/2018 Chapter 7 Test Review Absolutely no talking You have 7 minutes to review your exam – do not write anything on the test You will get your test back next class period and be given 20 minutes to adjust any answers. I suggest you make notes of items to study of questions to ask
5
Mendel’s Breeding experiments 8.1
11/11/2018 Mendel’s Breeding experiments 8.1 Gregor Johann Mendel’s history “Father” of genetics Bred garden peas (Pisum sativum) 1st to develop rules to predict patterns in inheritance of traits Quantitative Data!!!! Used very large samples Kept careful records Minimized errors (took time and stayed organized)
6
Key Terms I 7.1 Heredity Genetics Gene Cross
11/11/2018 Key Terms I 7.1 Heredity Passing traits from parents to offspring Genetics Branch of biology that studies heredity Gene Unit of DNA that controls traits Cross Mating or breeding of two individuals
7
Why peas? 8.1 Several traits take clearly different forms
11/11/2018 Why peas? 8.1 Several traits take clearly different forms Ex. Yellow or green seeds Male and female parts of peas are enclosed within the same flower Mating can be controlled as either: Self fertilization (self-pollination) Cross-pollination Mendel removed the stamens (male) from the flower of on plant and dusted the pistil (female) of another Peas are small, grows quickly, and produces many offspring Not to mention that the offspring can be used as food!!
8
From : http://www.people.virginia.edu/~rjh9u/monotraits.html
11/11/2018 From :
9
11/11/2018 Peas have 14 chromosomes (? Pairs) and each gene was on a different chromosome
10
Key Terms II Monohybrid cross True breeding (pure) P generation
11/11/2018 Key Terms II Monohybrid cross A cross that involves one pair of contrasting traits True breeding (pure) All offspring display the same form of the trait P generation 1st two individuals (mated or bred) F1 generation Offspring of P generation (F means filial) F2 generation Offspring of self-pollinated F1 generation
11
Example of a classic Mendel’s cross
11/11/2018 Example of a classic Mendel’s cross P generation Tall crossed with dwarf (both purebreeding) F1 generation All tall Self-pollinate a single example of F1 F2 generation 787 tall, 277 dwarf 2.84 : 1 ratio Close to a 3:1 ratio
12
Math Lab p. 165 “Calculating Mendel’s ratios” Copy the table
11/11/2018 Math Lab p. 165 “Calculating Mendel’s ratios” Copy the table Calculate the ratio State the ratio in words and then as a fraction Answer the final question
13
11/11/2018
14
Mendel’s Theory Historical perspective
11/11/2018 Mendel’s Theory Historical perspective Heredity was thought of as a blending of the two parents Mendel determined that there were two separate “heritable factors” for each trait Factors are called alleles (book says genes)
15
11/11/2018
16
11/11/2018 Mendel’s hypothesis 1. For each inherited trait, an individual has two copies of the gene – one from each parent. 2. There are different versions of genes. Alleles Receive one from each parent
17
Mendel’s hypothesis 3. Dominant allele recessive allele
11/11/2018 Mendel’s hypothesis 3. Dominant allele Can mask the presence of another allele Expressed whenever present Represented by a capital letter recessive allele Can be masked by the presence of a dominant allele Only expressed when contrasting allele is not present Represented by a lowercase letter (same letter as dominant)
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.