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Tuesday, January 8, 2013 1. List the thing you enjoyed the most over your holiday break? 2. State one fact you know about genetics/DNA. Warm Up. Genetics #1:. Introduction to Genetics & Gregor Mendel. Divide your paper Cues Section (1/3 page) Notes Section (2/3 page)
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Tuesday, January 8, 2013 1. List the thing you enjoyed the most over your holiday break? 2. State one fact you know about genetics/DNA. Warm Up
Genetics #1: Introduction to Genetics & Gregor Mendel
Divide your paper • Cues Section (1/3 page) • Notes Section (2/3 page) • At the END of today: • Draw a horizontal line at end of notes • 3-5 complete sentence summary of that day’s notes • Must include SPECIFICS Reminder: Cornell Notes
Describe the importance of Gregor Mendel. • Define the term traits. Objectives
Genetics = study of heredity • All living thing (plant, animal, or microbe) has a set of characteristics/traits • Inherit from parent(s)
Fertilization • Sexual reproduction • Male sperm & female egg join • Each haploid • Latin Root: hapl = single • Produce new cell • Diploid • Latin Root: diplo = double • Develops into embryo (seeds in plants) Review: Meiosis
Austrian monk, teacher, scientist, botanist • Studied peas in 19th century (1800’s) • Made observations • Designed experiments • Mathematical analysis • Known as Father of Genetics Gregor Mendel:
Bred peas in garden • Cross pollinated true breeding parent plants • Raised plants from seeds & made observations • Allowed offspring to self-bred & observed their offspring Gregor Mendel’s Work
True-breeding • AKA pure-bred • SAME characteristics seen in parent & offspring (IDENTICAL) • Do NOT see any other characteristics
The Original Plants • Plants in 1 section had different characteristics than plants in another section • Example: • Seeds #1 Tall plants • Seeds #2 Short plants • Plants #1 greenseeds • Plants #2 yellowseeds
Traits = specific characteristics (examples: seed/flower color, eye color, hair color) • Mendel studied 7 different pea plant traits
Worksheet: Karyotyping • Karyotype = picture of chromosomes • Used to detect chromosomal abnormalities ***Latin Root: karyo = nucleus***
Wednesday, January 9, 2013 • Who is the Father of Genetics? Warm Up
Genetics #2: Mendel’s Genetic Crosses, Dominance, Segregation
Contrast dominant and recessive alleles • Define the term allele. Objectives
Original generation of plants • Parents called P or “parental” generation • Bridget & Brendan are the parents therefore they are the P generation P P P generation
Offspring called F1 or “first filial” generation • Filius and filia are the Latin words for “son” and “daughter” • Kaya & Dorian are the children therefore they are the F1 generation F1 F1 F1 generation
= combination of 2 different things = offspring of crosses between parents w/ different traits • Ex: • Zonkey (donkey & zebra) • Liger (tiger & lion) • Toyota Prius (electric & gas) Hybrids
Cross Pollination = breeding 2 plants that have different characteristics • What did he do? • Crossed parent plants w/ different characteristics (tall, short, green seeds, yellow seeds) • Studied the offspring Mendel’s Cross Pollination Experiments
NO, all hybrids had characteristics of only ONE parents • In each cross, the character of the other parent seemed to disappear! What were the results? Mixture of all the traits?
= Have 2 different traits in parents, but only see 1 trait in offspring • Dominant Trait = Trait you see • Recessive Trait = Trait you do NOT see Parent: Blue Eyes Parent: Brown Eyes Dominance Child: Brown Eyes
Phenotype = physical characteristics • Example: brown or blue eyes • Genotype = genetic characteristics • Example: BB, Bb, or bb Phenotype vs Genotype
Genes = biological inheritance is determined by factors that are passed from one generation to the next (parent to offspring) • Alleles = different forms of a gene • One on every chromosome 1st Conclusion:
2nd conclusion: Principle of Dominance • States some alleles are dominant & others are recessive • An organism with a dominant allele will ALWAYS show the dominant trait
Result: All seeds yellow • Yellow seeds = Dominant • Green seeds = recessive Mendel’s Findings
Did they disappear? Did they segregate? • Experiment #2: • Crossed the different F1 generation • Made F2 generation What happened to the recessive traits?
Results: • Recessive traits reappeared • ¼ or 25% of the plants had recessive traits in F2 generation Mendel’s 2nd Experiment
F1 plants produced gametes (sex cells) • 2 alleles segregated from one another • each gamete carried a single copy of the gene • In the F1 generation, each gamete had 1 copy of the green gene or one copy of the yellow gene. • AKA Principle of Independent Assortment Conclusion: Mendel’s Law of Segregation
Directions: Design artwork for a t-shirt representing Mendel’s Genetics • 1) Front of shirt must have artwork showing the concept using 3 colors • 2) Back of the shirt must have a 1-2 line cute or clever (but clean) saying. • 3) A minimum of one paragraph (4-5 sentences) must be written to describe how the artwork and saying explain Mendel’s Genetics. Thinking Strategy #19 T-Shirt Design
Thursday, January 10, 2013 What is the difference between a dominant trait and a recessive trait? Warm Up
Genetics #3: Probability, Punnett Squares, Monohybrid Crosses
Define the term punnett square. • Predict the outcome of genetic crosses using punnett squares. Objectives
Probability = likelihood that an event will occur • Example: Coin toss • 2 possibilities: head or tails • probability of heads is 1 in 2 chance • i.e. ½ or 50% chance Genetics & Probability:
Example Problem: If you flip a coin 3 times in a row what are the chances that you will get heads every time? • Answer: • Toss #1 have a 1 in 2 chance • Same for Tosses #2 & #3 • ½ x ½ x ½ = 1/8 • 1 in 8 chance of flipping heads 3 times in a row! Genetics & Probability:
Principles of probability are used to predict the outcomes of genetic crosses Genetics & Probability:
= Diagram that shows the gene combinations that might result from a genetic cross Punnett Squares
Homozygous = 2 identical alleles (TT or tt) • Considered true-breeding • Latin Roots: Hom = same • Heterozygous = 2 different alleles (Tt) • Considered Hybrids • Latin Roots: Hetero = other, different Homozygous vs Heterozygous
Set up a Punnett square(Monohybrid Square) • 1.Set up a 2 by 2 Punnett square (monohybrid cross)
Set up a Punnett square 2. Write the alleles for parent 1 on left side of Punnett square • Each gamete will have 1 of the 2 parental alleles • 1/2 of the gametes will have the dominant (T) allele • 1/2 will have the recessive (t) allele
Set up a Punnett square 3. Write the allele for parent 2 above the Punnett square • This parent is heterozygous(Tt) • ½ the gametes will have the dominant (T) allele • 1/2 will have the recessive (t) allele
Fill in a Punnett square 4. Fill in the squares for parent 1. • Fill each square with the allele from Parent 1 that lines up with the row. T T t t
Fill in a Punnett square 5. Fill in the square for parent 2. • Fill each square with the allele from Parent 2 that lines up with the column. T T T t T t tt
25% 50% 25% homozygousheterozygoushomozygous dominant dominant recessive T T T t tt T t Genotypes that resulted from monohybrid cross (Tt x Tt)
75% Tall • TT = homozygous dominant • Tt = heterozygous dominant • 25% Short • tt = homozygous recessive Phenotypes that resulted from monohybrid cross (Tt x Tt)
Friday, January 11, 2013 • What is the difference between genotype and phenotype? • Using the letter “A,” give an example of a genotype that is homozygous dominant? Warm Up
Monday, January 14, 2013 • List the genotypes and their percentages for the punnett square above. Warm Up
Tuesday, January 15, 2013 Complete the following monohybrid punnett square: Warm Up
Genetics #4: Punnett Squares & Dihybrid Crosses