Practice: Codominance and Incomplete Dominance



Name:__________________________________________ Date: __________Practice: Codominance and Incomplete Dominance1. Practice setting up keys for the phenotypes listed in each set. Remember that the "medium" trait must always be heterozygous.a) Birds can be blue, white, or white with blue-tipped feathers.b) Flowers can be white, pink, or red.c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked.d) A Sneech can be tall, medium, or short.e) A Bleexo can be spotted, black, or white.2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are incomplete.Codominant _____________ Incompletely Dominant ________________Genetic Crosses that Involve 2 TraitsIn rabbits, grey hair is dominant to white hair. Also in rabbits, black eyes are dominant to red eyes.GG = gray hairGg = gray hairgg = white hairBB = black eyesBb = black eyesbb = red eyes1. What are the phenotypes (descriptions) of rabbits that have the following genotypes?Ggbb ____________________ ggBB ________________________ggbb ____________________ GgBb _________________________2. A male rabbit with the genotype GGbb is crossed with a female rabbit with the genotype ggBb The square is set up below. Fill it out and determine the phenotypes and proportions in the offspring.How many out of 16 have grey fur and black eyes? ____How many out of 16 have grey fur and red eyes? _____How many out of 16 have white fur and black eyes? ____How many out of 16 have white fur and red eyes? _____3. A male rabbit with the genotype GgBb is crossed with a female rabbit with the genotype GgBb The square is set up below. Fill it out and determine the phenotypes and proportions in the offspring.How many out of 16 have grey fur and black eyes? ____How many out of 16 have grey fur and red eyes? _____How many out of 16 have white fur and black eyes? ____How many out of 16 have white fur and red eyes? _____4. Show the cross between a ggBb and a GGBb. You'll have to set the square up yourself!?The Genetics of Blood Disordersright0001. ?If a female is a carrier for hemophilia ?X?H?X?h???and is married to a man with hemophilia ??X?h?Y , ?what is the probability that she will have a daughter with hemophilia?2. ?A normal female marries a man who has hemophilia . ?(You’ll need to figure out the genotypes). ?What percentage of their sons will have hemophilia? ?3. ?If a female has hemophilia and is married to a normal man. ?What percentage of her sons will have hemophilia? ?What percentage of her daughters will have hemophilia? ?4. A woman with sickle cell anemia is married to a man who is a carrier for the trait. ?( ?a ?a ??x ??A ?a). ?What is the chance of their children having sickle cell anemia?5. ?What is the chance that two people (both being carriers for sickle cell anemia) will have a child with the disease?Beyond Mendel – Codominance, Lethal Genes, Multiple Alleles, and Polygenic Traitsright0001. In a certain cactus, prickly spines can be two pronged or one pronged. If a true breeding one-pronged cactus is crossed with a true breeding two-pronged cactus, the F1 generation has a mixture of spines, some are two-pronged, and some are one-pronged.a. Is this an example of codominance or incomplete dominance?b. Show the F2 generation (a cross between the two F1's). What are the phenotypes of the offspring and in what proportion???2. In this same cactus, if you cross a plant that has red flowers to one that has yellow flowers, you produce a plant that has orange flowers.? Is this codominance or incomplete dominance??? Show the cross of an orange flowered plant to a red flowered plant.??3.?A red flowered, two-pronged cactus is crossed with a yellow flowered one-pronged cactus.? What are the resulting offspring and in what proportion???4. Show the cross of a cactus that is heterozygous for both traits crossed with one that has red flowers and one-pronged spikes.???5. A man with type A blood is married to a woman with type O blood.? What are ALL of the possible blood types of their children??6. A man with type AB blood is married to a woman with type O blood.? What are all the possible blood types of their children???7. Dwarfism in humans is a dominant trait that is also lethal if an individual inherits two copies. Show the genotypes of a family wear both parents are dwarfs and they have 2 children, where one is a dwarf and the other is not.???8. Guinnea pigs can have curly or straight hair, where the curly gene is recessive. Guinnea pigs can also have a condition called bowlegged, where their legs curve noticeably outward. Bowleggedness is a dominant lethal allele if an individual inherits two copies of it (BB). Show the cross between a curly haired, bowlegged guinnea pig and a heterozygous straight haired pig that is also bowlegged. How many of their offspring would you expect to be normal with curly hair?????9. In Snarlymonsters, the number of teeth is polygenic.? The recessive condition (aabbcc) results in a toothless Snarlymonster, and the dominant condition (AABBCC) results in a Snarlymonster with 6 teeth.? There are 5 other possible variations.How many teeth would an AaBbCc Snarlymonster have?? ______???10. List the phenotypic ratios (how many teeth) of all the potential offspring for the cross AABBCc? x? AAbbcc .???11. Lethal white overo syndrome is an autosomal recessive gene which if fatal 100% of the time and occurs in horses. Death of OLWS foals occurs within a few days of birth. If heterozygous, the animal has a multicolored patterned appearance, sometimes called a "paint". This pattern indicates the horse is heterozygous. If two of these horses were bred, what percentage of their offspring would be frame and what percentage would die from OLWS???? ................
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