Corn kernel activity

3/27 ATB What carries your genetic code? Today: Look over tests Start new chapter!

Chapter 11 Review What are autosomes? What does diploid mean? What is the difference between the cells produced in mitosis and meiosis? What is the purpose of mitosis How many sex chromosomes do you have? How many sex cells do you have? What is the purpose of meiosis? What is crossing over? What are homologous chromosomes?

3/28 ATB What type of plant did Mendel use in his experiments? Today: Show me your completed page 2 and 3 of your note packet First 15 minutes…complete the book assignment on page 3 of your note packet Rest of class…start the new chapter on genetics

Genetics

What is genetics? Scientific study of heredity Helps us understand what makes organisms unique

Brief History Gregor Mendel – Austrian monk One of 1st to study heredity Heredity - Transmission of characteristics from parents to offspring – studied pea plants Trait – genetically determined form of a characteristic Examples: Yellow color, pea shape (shriveled or round)

True Breeding What does it mean that Mendeal had peas that were “true breeding”? plants that, when self pollinated, always produce the same traits

Pollination Fertilization – Self-Pollination – Describe a trait When a male and female sex gametes fuse. Self-Pollination – when pollen is transferred to the stigma of the same plant Describe a trait Specific characteristic of an individual Examples: Seed color or plant height

Pollination – Cross-Pollination – when pollen is transferred from the anther of a flower to the stigma Cross-Pollination – when pollen is transferred to the stigma of a different plant

Genes and Alleles P generation – parent generation F1 Generation – 1st “filial” generation – offspring of the P generation (means son / daughter) F2 Generation – 2nd “filial” generation – offspring of the F1 generation What are genes? Factors that determine an individuals characteristics Alleles – various forms of a trait Allele for pea pod color – G = green and g = yellow

Dominant and Recessive Alleles What does the Principle of Dominance State? Some alleles are dominant and others are recessive Dominant – alleles that are always expressed (mask recessive) Recessive – alleles that are masked by dominant alleles Example: Pea pod color G = green pods g = yellow pods What will these offspring look like? GG gg Gg

Segregation Segregation of Alleles Alleles for height segregate (or separate) during gamete formation What are gametes? Sex cells This is saying that during gamete formation, the alleles for each gene segregate from each other so that each gamete only carries one allele for each gene So a sex cell can’t carry the 2 alleles for being tall

ASSIGNMENT: Page 312 Complete #1all, 2a and b.

Terms

A protein in a cell membrane changed its shape to move sodium and potassium ions against their concentration gradients. Which molecule was MOST LIKELY use by the protein as an energy source A) ATP B) ADP C) catalase D) amylase Today: Monohybrid cross perfection Go over tests 4/18 ATB

3/31 What does true breeding mean? Today: Review genetics Start punnett squares

Section 11.2 – Applying Mendel’s Principles

Probability What is probability? Likelihood that an event will occur. Cup game and probability!

Heterozygous – Homozygous – Genotype – Phenotype – when alleles for a trait are different (Gg) Homozygous – when alleles for a trait are the same (GG or gg) Genotype – genetic make up (Gg) Phenotype – organisms appearance (Green)

Monohybrid Cross – Punnett Square – when you make a cross for only one trait Example: Trait = pod color Cross: Yellow Pod x Green Pod Punnett Square – diagram used to show results of crosses

Monohybrid Cross Practice T = tall t = short R = round r = wrinkled W = white w = purple 1. Cross the following: TT x tt. What is the genotype ratio? What is the phenotype ratio?

2. Cross a heterozygous round plant with another heterozygous round plant. What is the genotypic ratio? What is the phenotypic ratio?

3. Cross a heterozygous white plant with a purple plant What is the genotypic ratio? What is the phenotypic ratio?

4/19 ATB Make a punnett square to complete the following cross. T = tall t = short Cross a heterozygous plant with a short plant. What are the genotypic and phenotypic ratios? Today: Finish discussion on monohybrid crosses Today is the last day we will really focus on the monohybrid crosses

Worksheet pages You must complete by the end of the period: Pg 28-29 – homework

4/22 ATB What is the phenotypic ratio of a cross of two heterozygous plants? Today: Go over worksheets from Friday Homework: Page 28-29. Discuss incomplete dominance / codominance Test – Thursday

Test Cross – Cross done to find the genotype of an organism Cross the unknown with a homozygous recessive

Law of segregation – Alleles for a trait separate during gamete formation So when we’re making our sex cells, the alleles (for forms of a trait) separate and are inherited independently (so a male pollen grain may have the allele for being green OR being yellow)

Law of Segregation – alleles from parents separate during gamete formation A) Copy of gene separates – so each sex cell only receives one copy (So a parent with GG donates “G” to one gamete and the other “G” another.)

Law of Segregation

Law of Independent assortment – Genes for different traits are transmitted independently of one another Means that different traits are not inherited together.

Dihybrid Crosses Dihybrid Cross – when you make a cross for two traits Example: Pod color AND plant height Flower color AND pod shape. Cross: Tall, Yellow Plant x Short, Green Plant

Cross a short, purple plant with a homozygous tall, heterozygous white plant. What is the phenotypic / genotypic ratios?

Dihybrid Cross Practice T = tall t = short W = white w = purple Cross a heterozygous tall, white plant with another heterozygous tall, white plant. What is the phenotypic / genotypic ratios?

Dihybrid cross practice Bottom of page 13 Page 26

Section 11.3 – Other Patterns of Inheritance

Incomplete Dominance – When one allele is not complete dominant over another Flower: Red x White = Pink

Codominance – Phenotypes of both alleles are clearly expressed Example: Red flower x white flower = red / white flower

4/23 ATB Give an example of codominance Today: Turn in page 28 and 29 from the packet Finish the notes Complete a dihybrid cross. Test Friday / Study guide Friday When do you want your study guides?

Multiple Alleles – Any gene with more than two alleles for the trait Example – Blood type is caused by 3 different alleles (type of codominance occurs) What are the various blood types in humans?

Blood type – Practice Cross Cross a person who is has AB blood with a person who has type O blood. What blood type will their offspring be? Cross a person with iAi with another individual that has iAiB. What are the possible blood types of their offspring?

Polygenic Traits – Traits controlled by two or more genes “many genes” Skin color in humans is a polygenic trait

4/24 ATB Create all the allele combinations for the following plant: GgWW (you should always have 4) Today: Finish discussing dihybrid crosses Describe meiosis Get study guides (try to have them done by tomorrow to ask questions) Test Friday / Study guide due Friday

MEIOSIS

Review: What is a haplid cell? What is a diploid cell? Cells with only one copy of chromosomes (sex cells) What is a diploid cell? Cells with two copies of chromosomes (body cells) What is the process that creates new body cells? Mitosis The cells produced by mitosis are genetically _____________. identical

Meiosis – Process of generating sex cells (haploid cells, 1n) Number of chromosomes per cell is cut in half through the separation of homologous chromosomes.

Mitosis vs. Meiosis

Crossing over – When homologous chromosomes line up they sometimes exchange genetic material This is why sex cells are genetically unique from all other cells.

The End

4/25 ATB What does the process of meiosis create? Are these cells identical or different from one another? Today: Review the chapter Questions from the study guide? Period 8 – turn in page 28 and 29 (put you name on both sheets) Test / Study guide -- FRIDAY

Test Review What does homozygous mean? Give an example. What does heterozygous mean? Give an example. What is a test cross? What is the difference between genotype and phenotype? In a monohybrid cross between a homozygous dominant parent and a homozygous recessive parent, what would the genotypic ratio of the offspring? A black chicken and a white chicken have an offspring with black and white feathers. What type of inheritance is this? If a trait occurs in 600 offspring out of 1,200. What is the % chance that an individual will have this trait?

Another practice dihybrid Cross a heterozygous tall, heterozygous green plant with a short, heterozygous green plant T = tall t = short G = green g= yellow Phenotypic ratio = ____________

4/26 ATB TEST! Turn in your study guides Start on #151 on the scantron

5-14 TEST! Any last questions? Get out your review sheets – turn them in You may write on the test…use a pencil on the scantron