Download
1 / 51
510 likes | 943 Views
Jeopardy. Mendel, Genotypes and Phenotypes. Punnett Squares. Meiosis. Non-Mendelian Inheritance. Pedigrees. Q $100. Q $100. Q $100. Q $100. Q $100. Q $200. Q $200. Q $200. Q $200. Q $200. Q $300. Q $300. Q $300. Q $300. Q $300. Q $400. Q $400. Q $400. Q $400. Q $400.
E N D
Jeopardy Mendel, Genotypes and Phenotypes Punnett Squares Meiosis Non-Mendelian Inheritance Pedigrees Q $100 Q $100 Q $100 Q $100 Q $100 Q $200 Q $200 Q $200 Q $200 Q $200 Q $300 Q $300 Q $300 Q $300 Q $300 Q $400 Q $400 Q $400 Q $400 Q $400 Q $500 Q $500 Q $500 Q $500 Q $500
$100 Question: Meiosis What is crossing over? During which phase of meiosis does crossing over take place?
$100 Answer: Meiosis Crossing over is when homologous chromosomes swap segments of DNA. Crossing over occurs during prophase I (or prometaphase I) of meiosis.
$200 Question: Meiosis A crayfish cell has 200 total or 100 pairs of chromosomes. Following mitosis, the daughter cells would each have a total of ______ chromosomes. After meiosis, the four daughter cells would have _____ chromosomes. • 200, 200 • 100, 100 • 100, 200 • 200, 100 • 46, 23
$200 Answer: Meiosis • d. 200, 100
$300 Question: Meiosis • Compare and contrast the daughter cells produced by meiosis to the parent cell in terms of: • Number of cells. • Chromosome number. • Composition of chromosomes. • Purpose of cells.
$300 Answer: Meiosis • Parent cell • 1 cell • 2n (diploid), in humans – 46. • Chromosomes have not gone through crossing over, so maternal and paternal chromosomes are separate. • Cells generate sex cells, gametes, sperm or eggs, etc. • Daughter cells • 4 cells • 1n (haploid), in humans – 23. • Chromosomes have gone through crossing over so maternal and paternal chromosomes have a mix of DNA; also, chromosomes have been assorted independently. • Cells are sex cells, gametes, sperm or eggs, etc.
$400 Question: Meiosis How are the processes of meiosis and fertilization shown in Punnett squares? How do Punnett squares illustrate Mendel’s laws of independent assortment and segregation?
$400 Answer: Meiosis Punnett squares show meiosis through the separation of alleles (Bb being separated into B and bs, for instance) – which is Mendel’s law of segregation – and in alleles assorting independently of one another (BbTt forming four kinds of gametes) – which is Mendel’s law of independent assortment.
$500 Question: Meiosis Disorders like Down Syndrome, Trisomy 13 Syndrome, etc. result when the zygote ends up with aneuploidy – an abnormal number of chromosomes. Plants sometimes end up polyploid – having a 3n or 4n chromosome number, which can found a new species of plant. Given what you know about meiosis, propose how both aneuploidy and polyploidy result.
$500 Answer: Meiosis Anueploidy and polyploidy both result from non-disjunction, when chromosomes fail to divide properly in meiosis. Aneuploidy generally results when one set of homologous chromosomes (for instance, chromosome 21 in the case of Down syndrome) fails to separate in anaphase I of meiosis. The resulting gametes have an abnormal number (22 or 24) of chromosomes. In plants, an entire set or sets of homologous chromosomes fail to separate, leading to gametes that are 2n or 3n, resulting in 3n or 4n offspring. (Or two plants can do this, each with 2n gametes, etc.) This results in plants having high chromosome numbers and sometimes the formation of a new species.
$100 Question: Mendel, Genotypes, and Phenotypes What is the difference between a genotype and a phenotype?
$100 Answer: Mendel, Genotypes, and Phenotypes Genotypes refer to an organism’s internal genetic code; phenotypes refer to an organism’s external appearance or behavior.
$200 Question: Mendel, Genotypes, and Phenotypes • Use the following traits to complete questions on genotypes, phenotypes and Punnett squares. • Two Antennae (A) vs. One Antennae (a) • Pointy Ears (I) vs. Round Ears (i) • A male has the genotype AA and is heterozygous for ear shape. His wife is heterozygous for antennae and ii for ear shape. What will their phenotypes be?
$200 Answer: Mendel, Genotypes, and Phenotypes Him: Two antennae, pointy ears. Her: Two antennae, round ears.
$300 Question: Mendel, Genotypes, and Phenotypes • During Mendel’s experiments, he crossed a pea plant with smooth peas with a pea plant with wrinkled peas. All the plants in the F1 generation had smooth peas. From this information, you can conclude: • a. The smooth allele is dominant to the wrinkled allele because the smooth allele hid the presence of the wrinkled allele. • b. The smooth and wrinkled alleles are codominant to each other. c. The smooth and wrinkled alleles are incompletely dominant to each other. • d. The wrinkled allele is dominant to the smooth allele because the wrinkled allele was hidden by the smooth allele.
$300 Answer: Mendel, Genotypes, and Phenotypes • a. The smooth allele is dominant to the wrinkled allele because the smooth allele hid the presence of the wrinkled allele.
$400 Question: Mendel, Genotypes, and Phenotypes An experimenter wants to determine if a plant with purple flowers is homozygous dominant or heterozygous for the trait. Purple flowers are dominant to white flowers. Design an experiment that would determine which genotype the plant has.
$400 Answer: Mendel, Genotypes, and Phenotypes Cross the plant with purple flowers with a plant with white flowers, which are always homozygous recessive. If half the offspring are white, the plant is heterozygous. If all the offspring are purple, then the plant is homozygous dominant.
$500 Question: Mendel, Genotypes, and Phenotypes Both pink and blue hydrangeas have the same genotype for flower color. Explain how the same genotype can produce two different flower colors.
$500 Answer: Mendel, Genotypes, and Phenotypes The hydrangea’s phenotypes are, in part, determined by the soil in which they are planted. Pink flowers result from acidic soils, blue flowers from basic soils and intermediate (purple) flowers from more neutral soils. Just as environment (sunlight, fake tanning) can influence phenotype in humans, it can also influence phenotype in plants.
$100 Question: Punnett Squares Perform the following cross: Ss x Ss. (S= short fur, s= long fur.) What are the genotypes and phenotypes of the offspring?
$100 Answer: Punnett Squares S s S s Genotypes: 25 percent homozygous dominant; 50 percent heterozygous; 25 percent homozygous dominant Phenotype: 75 percent short fur; 25 percent long fur
$200 Question: Punnett Squares • Hair color in humans is NOT sex-linked. Brown hair (B) is dominant to blond hair (b). A blond-haired woman has children with a male heterozygous for hair color. What percentage of their offspring are likely to have blond hair? • a. 0 percent • b. 25 percent • c. 50 percent • d. 75 percent • e. 100 percent
$200 Answer: Punnett Squares c. 50 percent
$300 Question: Punnett Squares Two parents heterozygous for two traits mate and have children. How many of their children are likely to be homozygous dominant for both traits?
$300 Answer: Punnett Squares One out of sixteen. AB Ab aB ab AB Ab aB ab
$400 Question: Punnett Squares An individual homozygous dominant for two traits (unattached earlobes and brown eyes) has children with an individual homozygous recessive for two traits (attached earlobes and blue eyes). WITHOUT performing a Punnett square, predict what the genotypes and phenotypes of the offspring will be.
$400 Answer: Punnett Squares All offspring will be heterozygous for both traits and have unattached earlobes and brown eyes.
$500 Question: Punnett Squares A scientist crosses two plants heterozygous for two traits and gets the following phenotypic ratios. Explain how these numbers could be so different from the expected phenotypic ratios.
$500 Answer: Punnett Squares These genes are located on the same chromosome, therefore they do not assort independently of one another. These are known as “linked” genes. When phenotypic ratios are significantly different from what we expect with independent assortment, we can conclude something else – such as gene linkage – may be at work. Depending on how frequently genes assort independently from one another, we can establish how far away from each other they are on a chromosome.
$100 Question: Pedigrees Two people in a pedigree are linked like this: What is the relationship between them?
$100 Answer: Pedigrees They are married. You can tell by the line connecting them.
$200 Question: Pedigrees In the above pedigree, people with brachodactylia, a dominant trait, are shaded in while people with a recessive trait are left blank. Use a B for brachodactylia and a b for normal fingers. What are the genotypes of II-8 and II-2? How do you know?
$200 Answer: Pedigrees II-8 - bb, because the person is homozygous recessive since his square is unshaded II-2 - Bb. The person must be heterozygous, since her parents are Bb and bb. To be shaded, she must have the dominant trait and cannot be BB.
$300 Question: Pedigrees The following pedigree shows the inheritance of a recssive trait in a family. Those with the recessive trait are shaded in red. What are the genotypes of I-1 and II-2? How do you know?
$300 Answer: Pedigrees I-1 is homozygous recessive because he shows the recessive trait. II-2 is heterozygous because half her children are homozygous recessive and half are heterozygous.
$400 Question: Pedigrees For the above pedigree, people with a trait have been shaded in. Is this trait dominant or recessive? HOW DO YOU KNOW?
$400 Answer: Pedigrees The trait is dominant. If it’s dominant, both parents are heterozygous and the affected offspring are either homozygous dominant or heterozygous. If a trait is dominant, then people with at least one allele for the trait will show the trait in their phenotype. If the trait is recessive, then those with the trait are homozygous recessive and cannot have offspring that have a dominant allele.
$500 Question: Pedigrees For the above pedigree, people with a specific trait have been shaded in red. Note that only males (squares) have the trait, while females may be carriers, but do not have the trait. Propose a possible system of inheritance for the trait that explains these observations.
$500 Answer: Pedigrees The trait displayed is hemophilia, which is known as a sex-linked trait. Sex-linked traits tend to be shown more in males, since males have the genotype XY. Because they only have one X chromosome, a trait, even a recessive trait, carried on that X will give them that phenotype. (They are known as ‘hemizygous’ since the X and Y chromosomes are non-homologous.) Sex-linked recessive traits are, as result, much more common in males than in females, who have a second X chromosome. This issue was compounded by the cousin-marriages practiced by European royalty, which means that a rare harmful allele became more common when people who were closely related married and had children.
$100 Question: Non-Mendelian Inheritance A red flower is crossed with a white flower. The resulting offspring are all pink. What kind of inheritance are these flowers showing?
$100 Answer: Non-Mendelian Inheritance This is incomplete dominance because the offspring resemble and intermediate of the two parents.
$200 Question: Non-Mendelian Inheritance A rabbit with black and white hair breeds with a rabbit with black and white hair. 25 percent of the resulting rabbits have black hair, 50 percent have black and white hair, and 25 percent have white hair. What kind of inheritance is displayed here? How do you know?
$200 Answer: Non-Mendelian Inheritance These rabbits are displaying codominant inheritance. We know because the rabbits can display two dominant traits (black and white fur) simultaneously.
$300 Question: Non-Mendelian Inheritance • A woman with type A blood is married to a man with type B blood. One of their children has type A blood. The man suspects that the child is not his (genetically). Can the child be his? SHOW YOUR WORK!
$300 Answer: Non-Mendelian Inheritance IAIA or IAi x IBi. IA IA IA i IB i IB i
$400 Question: Non-Mendelian Inheritance A person with type AB positive blood and a person with type O negative are rushed to a hospital in need of blood transfusions. Explain what kinds of blood each person can receive and why.
$400 Answer: Non-Mendelian Inheritance The AB positive person can receive all blood types: A pos and neg, B pos and neg, O pos and neg, and AB pos and neg. The type O negative person can only receive type O negative blood. People with Type AB blood, since they have A and B sugars, can receive both A and B blood. Everyone can receive O blood and their own blood type. Rh positive people can receive positive and negative blood. People with Type O blood can receive Type O and Type O only. People with negative blood can negative blood and only negative blood.
$500 Question: Non-Mendelian Inheritance People with red hair and pale skin often experience more dental pain than people of different hair colors and skin tones. Explain what could make this correlation possible, in terms of non-Mendelian genetics.
