EQ: How are genes responsible for the variety of organisms that exist? Mendel Genetics

Think-pair-share talk with your partner about why these puppies look different. Hypothesize why some look similar to the mom and some look different?

PTC tasting Complete pre-lab question. Participate in PTC paper tasting. Are you a taster or non-taster? What letters will be used to represent tasters and non-tasters?

Understanding Genetics Genetics – study of heredity and variations of inherited characteristics Gene- Piece of DNA that provides instructions for making protein

Understanding Genetics Inheritance- how characteristic and genes are passed from parent to child Heredity- the passing of traits form parent to offspring through genetics

Understanding Genetics Genotype Phenotype The genetic makeup of a specific set of genes An organism’s physical characteristics Can have same phenotype but DIFFERENT genotype

Types of Alleles Dominant Allele Recessive Allele Stronger of the two alleles Will always be expressed if present- only needs 1 copy Capital letter Expressed only when two copies of the allele are present Lowercase letter

Allele Any of the alternative forms of a gene; two alleles for each gene (one on each homologous chromosome) Each letter in the genotype represents one allele Two Types: Dominant & Recessive Combinations: Homozygous, Heterozygous Each parent passes one copy of each trait to their offspring

Homo = Same Homozygous Describes two of the same alleles at the same locus (point) 2 dominant alleles (HH) is homozygous Dominant 2 recessive alleles (hh) is homozygous recessive

Heterozygous Hetero = different Describes two different alleles at the same locus (point) (Hh) Carrier: a heterozygous individual who has one recessive allele; doesn’t have the disease, but can pass the recessive allele to offspring

P.S. - use appropriate scientific terminology, always! allele combinations Heterozygous (Hh) Homozygous Dom. (HH) Homozygous Rec (hh) Heterozygous Homozygous dominant Homozygous recessive Based on what you know about allele combinations, describe the genotype of each pair of homologous chromosomes above. P.S. - use appropriate scientific terminology, always!

Check for Understanding Determine whether the following is a genotype of a phenotype: Brown Hair PHENOTYPE

Check for Understanding Determine whether the following is a genotype of a phenotype: An individual has recessive alleles for a gene GENTOTYPE

Check for Understanding A particular allele codes for the shape of a pea. The letter “r” is used to represent this allele. The dominant form is a round form, the recessive form is wrinkled: What is the genotype of homozygous dominant? RR

Check for Understanding A particular allele codes for the shape of a pea. The letter “r” is used to represent this allele. The dominant form is a round form, the recessive form is wrinkled: What is the phenotype of homozygous dominant? ROUND

Check for Understanding A particular allele codes for the shape of a pea. The letter “r” is used to represent this allele. The dominant form is a round form, the recessive form is wrinkled: What is the genotype of homozygous recessive? rr

Check for Understanding A particular allele codes for the shape of a pea. The letter “r” is used to represent this allele. The dominant form is a round form, the recessive form is wrinkled: What is the phenotype of homozygous recessive? Wrinkled

Check for Understanding A particular allele codes for the shape of a pea. The letter “r” is used to represent this allele. The dominant form is a round form, the recessive form is wrinkled: What is the genotype of heterozygous dominant? Rr

What did Gregor Mendel say when he founded genetics? Father of Genetics Studied patterns of inheritance using pea plants Developed three laws of inheritance What did Gregor Mendel say when he founded genetics?  Woopea! 

Mendel’s law of Dominance When a dominant and a recessive allele are present (Hh) in a organisms genotype, the dominant allele will mask the recessive allele in the phenotype. Dominant trait will always show

Mendel’s law of segregation During the production of gametes, two copies of each gene (allele) separate so that offspring acquire one factor from each parent. Recall: what process produces gametes?

Law of Independent Assortment Inheritance of one trait does not influence the inheritance of a second trait Traits are inherited independently

How can two yellow peas form from green peas?

Analyzing inheritance Monohybrid cross- Examines the inheritance of one specific trait R R r Rr Rr Rr Rr r

Punnett squares A tool used to predict inheritance Show all possible genotypes of offspring inside the grid box Parents genotypes are on the outside

Punnett squares r r R Rr Rr R Rr Rr We will use R for the dominant allele (red color) and r for the recessive allele (white color). Identify the alleles that make up the genotype of each parent. Plant 1 = RR, Plant 2 = rr Then separate and distribute them along the top and left side of the square. (Law of Segregation) Complete the cross by placing two alleles in each box based on the outsides of the box r r R Rr Rr R Rr Rr

Offspring possibilities What are the possible genotypes? All heterozygous (Rr). What are the possible phenotypes? All red flowers. Ratio? Pheno Dom: Rec ( 4:0 ) Geno Homo dom: Hetero: Homo Rec 0:4:0

Check for understanding Cross a homozygous dominant Tall plant with a heterozygous tall plant. What are the PARENT genotypes? Possible offspring genotype? Phenotypes? t T Tt TT T Tt TT T

PTC testing Answer the post lab questions using your new knowledge of genetics

Inheritance practice- minion genetics C – level 2 voice H- ask three before me A- work on creating your minion based on the possible genetics M- remain seated at your table P – complete your own minion genetics Success!

Exit ticket time clear your desks except for something to write with and Do now

EXIT Ticket Using the terms and ideas you learned today, justify how it is possible for two parents with straight hair (dom.) to have a child with curly hair (recessive)