BIOLOGY 12 Punnett Squares.

Slides:



Advertisements
Similar presentations
The Basics of Genetics…the passing of traits
Advertisements

Fundamentals of Genetics
O T T F F S S E __ What comes next?.
2g. Know how to predict possible combinations of alleles in a zygote from the genetic makeup of the parents. 1.
Using a Punnett Square.
PROBABILITY & PUNNETT SQUARES It can be written as a: Fraction ____ Percent ____ ____________________ is the __________ that a particular _________________.
Punnett Squares Step by step how to guide. Putting it together Alleles represented by letters –Capital letters = dominant (T) –Lowercase letters = recessive.
End Show Slide 1 of 21 Copyright Pearson Prentice Hall 11-2 Probability and Punnett Squares.
Genetics: The Science of Heredity
11-2 Probability and Punnett Squares
Predicting the Traits of Offspring By Reginald Punnett.
Review What is an allele? What is a gene? Define phenotype. Define genotype. Each person inherits two Each person inherits two alleles for each gene, one.
6.3 Genetics and Predictions. You will be able to: 1.Explain how probability is used in genetic predictions 2.To construct a Punnett Square for monohybrid.
Mendel Carefully Accumulated Data And Realized That The Principles Of Probability Could Be Used To Explain The Results.
Punnett Squares When we know information about the genetic makeup of two parents, we can predict the genetic makeup of any possible offspring created between.
How to a Work Punnett Square A Step by Step Process.
HUMAN BIO 11 Genetics: Punnet Squares. Mendelian Genetics Alleles  a form of the gene Phenotype  physical appearance Genotype  the alleles a person.
7.2.9 Students know plant and animal cells contain many thousands of different genes and typically have two copies of every gene. The two copies (or alleles)
Foothill High School Science Department Intro To Genetics Probability & Punnett Squares.
11-2 Probability and Punnett Squares
Punnett Squares.
Probability and Punnett Squares
Mendel, Heredity and Punnett Squares
Probability and Punnett Squares
Predicting the Traits of Offspring
Predicting the Traits of Offspring
How to a Work Punnett Square
O T T F F S S E __ What comes next?.
Genetics Gregor Mendel *The father of genetics.
O T T F F S S E __ What comes next?.
O T T F F S S E __ What comes next?.
STUDYING HEREDITY Punnett Squares – a diagram that predicts the outcome of a genetic cross by considering all possible combinations of gametes in the.
Copyright Pearson Prentice Hall
PROBABILITY & PUNNETT SQUARES 11-2
Punnett Squares & Probability
PROBABILITY & PUNNETT SQUARES 11-2
7.L.4A.3 Develop and use models (Punnett squares) to describe and predict patterns of the inheritance of single genetic traits from parent to offspring.
Probability & Heredity: Punnett Squares
Punnett Squares.
Punnett Squares & Probability
Genetics Crosses Ch. 9.2 (p )
Segregation of gametes
Mendel and Inheritance of Traits Notes
Section 2: Probability and Heredity
O T T F F S S E __ What comes next?.
Gene Symbols And Punnett Squares
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
O T T F F S S E __ What comes next?.
Heredity: Monohybrid Cross 5.3
Probability and Punnett Squares
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Predicting the Traits of Offspring
11.2 – Applying Mendel’s Principles
Predicting the Traits of Offspring
11-2 Probability and Punnett Squares
Copyright Pearson Prentice Hall
Copyright Pearson Prentice Hall
Predicting genetic outcomes
Punnett Squares & Probability
Copyright Pearson Prentice Hall
Genetics and Probability
Punnett Squares.
Predicting the Traits of Offspring
Monohybrid Crosses: Inheritance of single genes
Copyright Pearson Prentice Hall
Punnett Squares & Probability
O T T F F S S E __ What comes next?.
Copyright Pearson Prentice Hall
Presentation transcript:

BIOLOGY 12 Punnett Squares

the Punnett Square is a diagram that is used to predict an outcome of a particular cross or breeding experiment it shows all the possible combinations of alleles in offspring used by biologists to determine the probability of an offspring having a particular genotype

Sample Problem: in pea plants, tall pea plants are dominant over short pea plants using Punnett Squares, you can predict the genotypes and phenotypes of the offspring of a cross between a homozygous (purebred) tall pea plant and a homozygous (purebred) short pea plant.

Making Punnett Squares Step 1: designate letters which will represent the genes/traits capital letters represent dominant traits, and lowercase letters represent recessive traits T = tall t = short

Making Punnett Squares Step 2: write down the genotypes (genes) of each parent these are often given to you or are possible to determine TT X tt

Making Punnett Squares Step 3: draw a Punnett square - 4 small squares in the shape of a window write the alleles of one parent across the top write the alleles of the other parent along the left side of the Punnett square

Making Punnett Squares Step 4: fill in each box of the Punnett square by transferring the letter above and to the left into each appropriate box as a general rule, the capital letter goes first and a lowercase letter follows

Making Punnett Squares Step 5: list the possible genotypes and phenotypes of the offspring for this cross

the letters inside the boxes indicate probable genotypes (genetic makeup) of offspring resulting from the cross of these particular parents there are 4 boxes, and the genotypic results can be written either as fractions or percents in this case, all 4 boxes out of the 4 are showing the Tt genotype; therefore, each of the offspring has a 4/4 or 100% chance of showing the Tt genotype

we also have to write the phenotype (physical appearance) in each box under the genotype remember, T = tall and t = short (step 1) since a capital letter indicates a dominant gene, T (tall) is dominant over t (short); therefore, each of the offspring has a 4/4 or 100% chance of being tall

Conclusion punnett squares give us the probability of genotypes and phenotypes for each offspring

Single-Trait Inheritance Example: cross between a pea plant that is heterozygous for round seeds and a pea plant that has wrinkled seeds. Round is dominant (R) determine the genotypes and phenotypes of the offspring