1 / 10

GENETICS

Learn how to use Punnett squares to make predictions about the possible genotypes and phenotypes of offspring based on inherited characteristics. Discover the rules and vocabulary associated with Punnett squares and explore examples to understand the results. Practice completing Punnett squares to determine genotype and phenotype ratios.

joannetorres
Download Presentation

GENETICS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. T T Tt GENETICS t t PUNNETT SQUARE

  2. EXPECTATION Make predictions about possible outcomes of various genetic combinations of inherited characteristics.

  3. PUNNETT SQUARE RULES MOTHER’S GENES A Punnett square is a tool used to predict the possible genotypes for the offspring of two known parents. FATHER’S GENES

  4. VOCABULARY

  5. PUNNETT SQUARE Mother • The parent’s alleles go on the OUTSIDE of the square. R R RR X rr r Father r

  6. HOW TO USE A PUNNETT SQUARE 1. The parent’s alleles go on the OUTSIDEof the square. 2. DROP the letters on the top into each square. R R r Rr Rr NOTE: The ORDER does not matter in the boxes, but uppercase first is a good rule. r 3. MOVE each letter on the side into each square. Rr Rr

  7. HOW TO USE A PUNNETT SQUARE WHAT DO THE RESULTS SHOW? RESULTS: B B GENOTYPE %: 0 % BB 100% Bb 0 % bb 4:0 ALL Bb If B is the DOMINANTallele for BLACK b Bb Bb And b is the RECESSIVE allele for BROWN b PHENOTYPE %: 100% BLACK 0 % BROWN 4:0 RATIO, BLACK TO BROWN Bb Bb Then, we can make predictions about the outcomes.

  8. HOW TO USE A PUNNETT SQUARE LET’S LOOK AT ANOTHER PUNNETT SQUARE AND PREDICT THE OUTCOME. WHAT ARE THE RESULTS? T t GENOTYPE: 1TT: 2Tt: 1tt 1:2:1 RATIO 25 %TT, 50% Tt, 25% tt Tt T is the DOMINANTallele for tallness. TT T PHENOTYPE: 75% TALL 25% SHORT 3 : 1 RATIO: TALL TO SHORT t is the RECESSIVE allele for shortness. t tt Tt

  9. PUNNETT SQUARE PRACTICE Complete Punnett Square: • Yellow is dominant (Y). • Green is recessive (y). • Father - yy • Mother - Yy • Identify the phenotype and genotype. SeedColor

  10. PUNNETT SQUARES KEY Complete Punnett Square: SeedColor • Yellow is dominant (Y) • Green is recessive (y) • Father - yy • Mother - Yy • Genotype - 50% Yy: 50% yy • Phenotype - 50% Yellow 50% green y Y y yy Yy y yy Yy

More Related