monohybrid crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid...
TRANSCRIPT
![Page 1: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/1.jpg)
Punnett Squares 1
Monohybrid Crosses
![Page 2: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/2.jpg)
TEKS
• 6F: Students will…
predict possible outcomes of
genetic combinations such as
monohybrid crosses, dihybrid crosses,
and non-Mendelian inheritance
![Page 3: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/3.jpg)
Gregor Mendel
• Studied the different physical characteristics of pea plants
• Noticed characteristics of the offspring resembled their parents
• This passing of traits from parents to offspring is called heredity
• Genetics = scientific study of heredity
![Page 4: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/4.jpg)
Genetics Vocabulary
• Gene = segment of DNA where genetic
instructions for traits are found
![Page 5: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/5.jpg)
Genetics Vocabulary
• Allele = different versions of genes (ex: the gene
for eye color can be determined by a brown allele or a blue allele)
![Page 6: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/6.jpg)
Genetics Vocabulary
• Dominant = the allele that is stronger and ALWAYS expressed (covers up the recessive allele)▫ Represented with a capital letter
• Recessive = the weaker allele; only seenwhen found on BOTH chromosomes▫ Represented with a lowercase letter
• *An allele being recessive or dominant has nothing to do with how common it is
![Page 7: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/7.jpg)
Genetics Vocabulary
• Homozygous = both alleles are the same(dominant OR recessive)
• Heterozygous = each allele is different (one dominant, the other recessive)
![Page 8: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/8.jpg)
Genetics Vocabulary
• Genotype = represents the genetic code (letters) for each allele
Three types Homozygous dominant (BB)
Homozygous recessive (bb)
Heterozygous (Bb)
• Phenotype = physical appearance seen BECAUSE of the genetic code
Example: Blue or brown eyes
![Page 9: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/9.jpg)
Genetics Vocabulary
![Page 10: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/10.jpg)
Genetics Vocabulary
• Monohybrid: mating between two individuals with different alleles fora single gene
• Dihybrid: mating between two individuals with different alleles for two genes
![Page 11: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/11.jpg)
Mendel’s Laws
• Law of Segregation
▫ During the formation of gametes, the two allelesresponsible for a trait separate from each other
▫ Alleles for a trait are then “recombined” at fertilization, producing the genotype for the traits of the offspring
![Page 12: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/12.jpg)
Mendel’s Laws
• Law of Segregation
![Page 13: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/13.jpg)
Mendel’s Laws
• Law of Independent Assortment
▫ Alleles for different traits are distributed to sex cells (and therefore offspring) independently of one another
▫ This law can be illustrated using dihybrid crosses
▫ Dihybrid cross = a breeding experiment that tracks the inheritance of two traits
Number of gametes formed = 2n
*(n = # of heterozygous traits)
![Page 14: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/14.jpg)
Mendel’s Laws
• Law of Independent Assortment
![Page 15: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/15.jpg)
Mendel’s Laws
• Law of Dominance
▫ In a cross of parents that are homozygous forcontrasting traits, only one form of that trait will appear in the next generation
▫ All the offspring will be heterozygous andexpress only the dominant trait
▫ Ex: one parent is homozygous for brown eyes and the other is homozygous for blue eyes. All offspring will have brown eyes
BB x bb Bb
![Page 16: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/16.jpg)
Mendel’s Laws
• Law of Dominance
![Page 17: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/17.jpg)
Probability and Independence of Events
• Probability▫ The number that describes how likely it is that an
event will occur
▫ Usually written as a percentage
▫ Example: probability of a coin toss – heads or tails
There are two possibilities each time you toss the coin – heads or tails –each is as likely as the other
The probability of heads is 1 in 2, which is the sameas the probability for tails
This can also be expressed as a fraction – ½
That fraction can be converted into a percent – 50%
![Page 18: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/18.jpg)
Probability and Independence of Events
• Probability (cont.)▫ Keep in mind that this is a prediction of what is
LIKELY to occur, not necessarily what WILL occur
The more tosses you make, the closer your actualresults will be to the prediction
• Independence of Events▫ One event has no effect on another
▫ For our coin toss example – the results of the first toss do not affect the results of the second, and so on
![Page 19: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/19.jpg)
Punnett Square
• Also called a genetic cross
• One parent’s traits are placed at the top of the box
• The second parent’s traits are placed along the side of the box
• The traits of the offspring are placed inside the box
![Page 20: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/20.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 21: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/21.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 22: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/22.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 23: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/23.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 24: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/24.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 25: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/25.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 26: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/26.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 27: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/27.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 28: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/28.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 29: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/29.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 30: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/30.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 31: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/31.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 32: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/32.jpg)
Let’s Try One Together
• Parents: Bb x Bb
![Page 33: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/33.jpg)
Determining Ratios - Genotypic
• Parents: Bb x Bb
• Offpspring:
▫ ¼ = 25% BB
▫ 2/4 = ½ = 50% Bb
▫ ¼ = 25% bb
• 1:2:1 genotypic ratio
![Page 34: Monohybrid Crossesscienceinthemaking.weebly.com/.../1._punnett_squares_-_monohybri… · monohybrid crosses, dihybrid crosses, and non-Mendelian inheritance. Gregor Mendel •Studied](https://reader034.vdocuments.mx/reader034/viewer/2022051511/60046e018a1dea236c73b53c/html5/thumbnails/34.jpg)
Determining Ratios – Phenotypic
• Parents: Bb x Bb
• Offspring:
▫ ¾ = 75% brown
▫ ¼ = 25% blue
• 3:1 phenotypic ratio