Genetics Objective: Monday, October 29th

Genetic Counselor

Branch of biology that studies heredity Biological inheritance -passing things on from one generation to the next GENETIcS Branch of biology that studies heredity

Gregor Mendel Austrian monk and scientist Identified principles of genetics by studying pea plants Picked peas because of 7 observable traits, traits appeared and disappeared, small and grow easily and can self pollinate. Gregor Mendel

Mendel’s Experimental Design Started with pure parents of varieties (ex. Purple or white flowers) – P generation Cross pollinated parents to get F1 generation Self pollinated the offspring – F2 generation – Every time got a 3:1 ratio of the 2 varieties.

Many genes have different form ex Many genes have different form ex. Tall or short pea plants Variants of a particular gene = Alleles Alleles

DOMINANT TRAIT Recessive Trait the trait that masks the recessive trait. Recessive Trait the trait that was not expressed in Mendel’s F1 generation.

Meiosis and The Laws of Heredity Tuesday, October 30th

Gametes Meiosis produces haploid gametes (sex cells) Haploid means half of the genetic material to make a fertilized zygote (embryo) Diploid is a full double set of genes When gametes combine in fertilization, the number of chromosomes is restored (diploid).

Meiosis Similar to mitosis but sexual reproduction Goes through same stages as mitosis but twice Forms specialized sex cells called gametes Two rounds of nuclear division 2 stages called meiosis I and meiosis II

LAWS OF HEREDITY LAW OF SEGREGATION - members of each pair of alleles separate when gametes are formed.

Law of Independent Assortment pairs of alleles separate independent of each other during gamete formation.

THEORY OF HEREDITY 1. Parents do not transmit traits but genes that control traits.

2. For each trait an individual has 2 genes; one from MOM and one from DAD. P p HOMOZYGOUS - both have same info ex. PP (purple) or pp (white) HETEROZYGOUS - both have different info ex. Pp

PHENOTYPE - physical appearance Ex. Purple flower GENOTYPE - actual set of alleles PP or Pp or pp

The presence of an allele does not necessarily guarantee that it will be expressed. In heterozygous individuals only the dominant allele is expressed

Punnett Squares

What is a Punnett Square? a diagram that is used to predict an outcome of a particular cross used by biologists to determine the probability of an offspring having a particular genotype. Summary of every possible combination of one maternal allele with one paternal allele for each gene being studied

Dihybrid Cross If 2 traits are coded for on different genes there will be 16 different possible outcomes

Dihybrid Cross

Meiosis / Genetics Mini Quiz November 5th, 2012

1. 4. 2. 3.

5. Gregor __________________, the "father of genetics“ 6 5. Gregor __________________, the "father of genetics“ 6. The plants Mendel did his studies on: __________________ 7. The allele that is masked or covered up by the dominant allele: _______________________ 8. Square used to determine probability and results of cross: _______________________

9. What are the possible genotypes? 10. Will the offspring resemble mother or father more? Why

LAWS OF HEREDITY Law of ____________- members of each pair of alleles separate when gametes are formed. 11.

12. 13. ________ = Branch of biology that studies heredity _________ = Biological inheritance -passing things on from one generation to the next 13. ________ = Branch of biology that studies heredity

Phenotype Alleles Homozygous Heterozygous 14. 17. 15. 16. 18. Genotype Homozygous Heterozygous 14. variants of a particular gene are referred to as ?? physical appearance Ex. Purple flower 17. 15. both have same info ex. PP (purple) or pp (white) 16. - both have different info ex. Pp 18. actual set of alleles PP or Pp or pp

r R R r 19.Fill in the Punnett Square below 20. What is the genotypic ratio? 21. What is the phenotypic ratio? r R R r

Dihybrid Cross – 4 points Rraa x RRAa Figure out mom and dad gametes and then fill out the punnett square

Answers Heredity Genetics Anaphase Alleles Metaphase Homozygous Heterozygous Phenotype Genotype Punnett Square filled out 1:2:1 3:1 22-25 Work through as class on slide Anaphase Metaphase Telophase Prophase Mendell Peas Recessive Punnett Bb Father Segregation

WHEN HEREDITY FOLLOWS DIFFERENT RULES

Incomplete Dominance X Pink Flower (RR’) When the phenotype of the heterozygous individual is intermediate between the homozygous dominant and recessive individuals. Ex. Red flower (RR) X White flower (R’R’) Pink Flower (RR’)

Codominance When both traits appear equally in the heterozygous individual Ex. Blood types

Sex Determination 50% Chance for male or female

Sex Linked Traits When Traits are located on the sex chromosomes (X and Y) More traits are on the X than Y

Pedigree Graphic representation of an individual’s family tree, which permits patterns of inheritance to be recognized.

EX. Mrs. Carollo’s Family Eye Color Trait = Brown Eyes Female with trait Female without trait Male with trait Male without trait

Karyotype organized profile of chromosomes in single cell used to identify genetic disorders

Karyotype… how can I see it? Cell stained Take picture through microscope just before cell division Chromosomes are easiest to see at this point.

Normal Female, 46, XX

Normal Male, 46 XY

Kleinfelter’s Syndrome, 47, XXY

Turner’s Syndrome, 45, XO

Down’s Syndrome, 47, Trisomy 21

Gene Technology and Agriculture November 9th Video from desktop

Discussion Questions completed and discussed prior to, during, and after video How would you define gene technology? What role can gene technology have on agriculture in our country? What are some examples of gene technology used in the video? Does ethics play a role in gene technology? In what ways? Does gene technology alter the nutritional value of health of a product?