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Mendelian Genetics
Biology
Question | Answer |
---|---|
Who is considered to be the ''Father of Genetics¨? | Gregor Mendel |
What organism did Mendel use to come up with his ideas about inheritance? | A pea plant |
Why was this organism a good choice for Mendel? | They are not complex, only have 2 distinct versions of genes, and reproduce rapidly. |
What is the difference between a character and a trait? | A character is a category & a trait is a single object in the category (Ex. eye color vs blue eyes). |
How many characters did Mendel observe in his plants? | 7 |
How many possible traits were there for each character in Mendel's plants? | 2 |
What is an allele? | Different forms of a gene. |
How many alleles did each character have in Mendel's experiment? | 2 |
How many alleles does each parent pass on to their offspring? | 1 |
What does dominant mean? | Strong gene, always expressed if there. |
How do we represent a dominant allele? | Capital letter |
What does recessive mean? | Weak gene |
How do we represent a recessive allele? | Lower case letter. |
What does homozygous mean? | Same (letters in the allele), True breeding (gg x GG) |
What does heterozygous mean? | Different (letters in the allele) |
What is a genotype? | Sequence of letters |
What is a phenotype? | Visible trait |
Give an example of a homozygous dominant genotype. | PP, TT, HH, FF |
Give an example of a homozygous recessive genotype. | pp, tt, hh, ff |
Give an example of a heterozygous genotype. | Pp, Tt, Hh, Ff |
How can we use the heterozygous genotype to determine what the dominant trait is? | The heterozygous phenotype always shows what the dominant trait is. |
What is the law of dominance? | Some alleles are dominant & some are recessive, dominant expressed. |
What is the law of segregation? | Only one allele is passed on, everyone has 2 alleles. |
What is the law of independent assortment? | Genes for different traits that segregate independently do not influence each other's inheritance, one gene has no effect on another. |
What is the Punnett Square used for? | Calculates probability of inheritance. |
What are the six steps to making a Punnett Square? | 1. Determine genotype of parents 2. Write the cross 3. Make the square 4. Split parent alleles & put on sides 5. Fill in the square 6. Analyze results |
What do the letters on the sides of the Punnett Square represent? | The alleles the parents can pass on. |
What side of the Punnett Square do we usually put the father's alleles? | The top |
What side of the Punnett Square do we usually put the mother's alleles? | The side |
What do the letters inside the boxes of the Punnett Square represent? | Possible genotypes of the offspring. |
Mendel's P generation were considered to be true breeders. What does this mean? | Pea's will produce offspring identical to themselves & self pollination is required. (Completely homozygous) |
What were the genotypes and phenotypes of the parents in Mendel's P generation? | PP Purple & pp White |
What were the genotypes and phenotypes of Mendel's F1 generation? | Pp All Purple |
What did Mendel do with the F1 generation in order to create the F2 generation? | He cross bred them. |
What were the genotypes and phenotypes of Mendel's F2 generation? | PP Purple, Pp Purple, pp White |
What was the phenotypic ratio of the F1 generation? | 4:0 |
What was the phenotypic ratio of the F2 generation? | 3:1 |
What is a hybrid? | The offspring of crosses between parents with diffrent traits |
What is a monohybrid cross? | 1 trait |
What is a dihybrid cross? | 2 traits |
List all the possible allele options for DD | D |
List all the possible allele options for Rr | R, r |
List all the possible allele options for RrTt | RT, Rt, rT, rt |
List all the possible allele options for Gghh | Gh, gh |
What is incomplete dominance? | Neither allele is dominant, blend. |
Give an example of an incomplete dominance? | Red flower + White flower = Pink flowers |
What is Co-Dominance? | Neither allele is dominant or recessive, get both traits. |
Give an example of a Co-Dominance character? | Red cow + White cow = Roan Cow not Pink |
Make a Punnett Square for: A homozygous recessive white bunny and heterozygous black bunny | Answers: Bb, Bb, bb, bb |
Make a Punnett Square for: A purple flower with round seeds (PPRr) and and a purple flower with wrinkled seeds (Pprr) | Answers: PPRr, PpRr, PPrr, Pprr |
Make a Punnett Square for: A heterozygous pink flower and a homozygous red flower (use incomplete dominance) | Answers: RR, RR, RW, RW |
Make a Punnett Square for: A roan cow and a white cow (use co-dominance) | Answers: RW, RW, WW, WW |
What is the equation for Chi-Square? | X²=Σ (o-e)²/e |
What does a Chi-Square test really test for? | It test the goodness of fit. |
How do you figure out what degree of freedom to use? | Number of phenotypes/categories minus 1. |
What percentage must be obtained for an acceptable value for the difference in data? | 5% or 0.05 |
A brown eyed man (father had blue eyes and mother had brown eyes) is married to a brown eyed woman (parents both had brown eyes) they have two children, one with brown eyes and one with blue eyes. What are the genotypes of all the individuals involved? | Grandmother (Dad): B? Grandfather (Dad): bb Dad: Bb Grandfather/mother (mom): BB or Bb (one has to be Bb) Mom: Bb Children: B?, bb |
You cross a heterozygous purple flower with a homozygous white flower. Your results show that you produced 687 purple flower plants and 614 white flower plants. Perform a chi-square test to explain if the data is a good fit. | Punnett Square Answers: Pp, Pp, pp, pp Observed: 687 Purple, 614 White, 1301 Total Expected: 650.5 Purple, 650.5 White X²= 4.096 No, this is not a good fit because it is not within 5% |
What is a pedigree? | A diagram showing genetic relationships between members of a family. It is used to analyze patterns of inheritance for specific genetic traits. |
How can you tell what the dominant trait is in a pedigree? | Look for two of the same parents that have a different child (the parents are dominant). |