Mendelian Genetics & Inheritance Patterns. Practice Questions. Slide 1 / 116. Slide 2 / 116. Slide 3 / 116

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1 New Jersey Center for Teaching and Learning Slide 1 / 116 Progressive Science Initiative This material is made freely available at and is intended for the non-commercial use of students and teachers. These materials may not be used for any commercial purpose without the written permission of the owners. NJCTL maintains its website for the convenience of teachers who wish to make their work available to other teachers, participate in a virtual professional learning community, and/or provide access to course materials to parents, students and others. Click to go to website: Slide 2 / 116 Mendelian Genetics & Inheritance Patterns Practice Questions 1 Sexual reproduction takes a very significant toll on those species that utilize this process. What is the benefit that sexual reproduction offers for a species? Slide 3 / 116

2 2 What is the relationship between traits and heredity? Slide 4 / Explain the concept of Blending Inheritance. Was this theory supported or rejected by Mendel and his work? Slide 5 / Explain, in terms of the theory of Inherited Characteristics, how an anteater has developed a long nose. Slide 6 / 116

3 5 Identify the characteristics that made pea plants ideal for Mendel to use as a model organism. Slide 7 / Explain the process by which Mendel was able to control his breeding between pea plants. Slide 8 / What is a phenotype? Slide 9 / 116

4 8 Pick three traits Mendel chose to observe and identify two potential phenotypes for each trait. Slide 10 / What is true breeding? Slide 11 / Identify the ratio of offspring for the F1 and F2 generations in a monohybrid cross involving parents with white and purple flowers. Slide 12 / 116

5 11 Identify the four rules that Mendel established following his studies of the monohybrid cross process. Slide 13 / What is it called when an organism possesses two different alleles for a trait? Slide 14 / Explain how the ratio of the F2 generation in Mendel s monohybrid crosses helped him to determine the existence of dominant and recessive alleles. Slide 15 / 116

6 14 What is the Law of Segregation? Slide 16 / Identify the relationship between meiosis and Mendel s patterns of inheritance. Slide 17 / Suppose one of Mendel s pea plants had experienced a non-lethal form of trisomy for one of the characteristics he was studying. Explain how this could have complicated Mendel s observations if this plant were part of a parent generation in one of his monohybrid crosses. Slide 18 / 116

7 17 Suppose Mendel had made his observations a few decades later when there as more widespread knowledge of chromosomes throughout the scientific community. How do you suppose this may have impacted the development of his theory? Slide 19 / is widely considered to be the father of modern genetics because of the role that he played in the development of this field. Slide 20 / What is the concept of Inheritance of Acquired Characteristics? Explain this theory and identify the individual who developed the theory. Slide 21 / 116

8 20 What is a model organism? Identify Mendel s model organism. Slide 22 / Why was it essential that Mendel was able to control breeding between his pea plants? Slide 23 / Identify the details regarding the phenotypes investigated by Mendel that contributed to the ideal nature of his model organism. Slide 24 / 116

9 23 What is a monohybrid cross? Explain the steps involved in this process and identify the names of the generations involved. Slide 25 / Compare the phenotypes of the F1 generation with the phenotypes of the P generation in a monohybrid cross. Slide 26 / What did Mendel conclude regarding inheritance of alleles from his monohybrid cross experiments? Slide 27 / 116

10 26 What is it called when an organism possesses two copies of the same allele for a given trait? Slide 28 / Why did Mendel never discuss chromosomes in the development of his theories on genetics? Slide 29 / What is the relationship between homologous chromosomes and allele pairs described in Mendel s theories of inheritance? Slide 30 / 116

11 29 What is a heritable factor? Slide 31 / What is the difference between a homozygous and heterozygous allele combination? Slide 32 / Explain the purpose of a Punnett Square. Slide 33 / 116

12 32 What is the difference between a genotype and a phenotype? Slide 34 / Identify the genotypes of the P generation involved in Mendel s monohybrid crosses. Slide 35 / Suppose large ears (L) are dominant over small ears in elephants. Cross an elephant with small ears with a heterozygote elephant. What are the genotypic and phenotypic ratios? Slide 36 / 116

13 35 Suppose broad stripes (B) are dominant over skinny stripes in tigers. If two heterozygote tigers produce a cub, what is the percent chance that the cub will have skinny stripes? Slide 37 / Suppose the allele for blue color (B) is dominant to the allele for yellow in a flower species. What combination of parent genotypes could potentially yield yellow offspring? Slide 38 / Are offspring genotypic and phenotypic ratios always the same? Explain your answer. Slide 39 / 116

14 38 What is the purpose of a test-cross? Slide 40 / In Mendel s pea plants, tall was the dominant allele for plant height. Perform a test cross to determine the unknown genotype of a tall pea plant. Provide both possible outcomes. Slide 41 / Why does it make sense that test-crosses are more accurate and reliable involving species that reproduce with multiple offspring at one time? Slide 42 / 116

15 41 What is the difference between a monohybrid and dihybrid cross? Slide 43 / Suppose in eagles, short wings (S) are dominant over long wings (s) and sharp talons (T) is dominant over dull talons (t). Cross an eagle heterozygous for both traits with an eagle homozygous recessive for both traits. Provide genotypic and phenotypic ratios for offspring. Slide 44 / Suppose in lions, long tail (L) is dominant to short tail and solid coat (S) is dominant to mottled coat. Cross a lion homozygous recessive for tail length and heterozygous for coat with a lion heterozygous for tail length and homozygous dominant for coat. Provide genotypic and phenotypic ratios. Slide 45 / 116

16 44 Explain, in terms of probability, why the chances of producing two organisms that are genetically identical decreases as the number of genes in a genome increase. Slide 46 / Use the rule of multiplication to determine the following: Suppose you cross an organism with the genotype AaBbCc with an organism with the genotype aabbcc. What is the probability that the offspring will have the genotype aabbcc? Slide 47 / Use the rule of addition to determine the following: Suppose you cross two pea plants heterozygous for flower color (remember purple is dominant to white). What is the probability the offspring will be a heterozygote? Slide 48 / 116

17 47 Use the rule of addition to determine the following: Suppose you cross two pea plants heterozygous for flower color (remember purple is dominant to white). What is the probability the offspring will be purple? Slide 49 / Use the rules of multiplication and addition to determine the following: Suppose you cross two individuals with the following genotypes: AABbCC x aabbcc. What is the probability that you will produce an offspring with genotype AaBBCC or AaBbCc? Slide 50 / In developing a Punnett Square, what do the letters actually represent? Slide 51 / 116

18 50 In Mendel s monohybrid cross, which allele is expressed in a heterozygous genotype? Slide 52 / In Mendelian traits, is it always possible to determine the genotype of an organism with a dominant phenotype? Explain your answer. Slide 53 / Suppose in pine trees long needles (L) are dominant to short needles. Cross a homozygous dominant tree with a short-needled tree. Provide genotypic and phenotypic ratios. Slide 54 / 116

19 53 Suppose in great white sharks that a tall dorsal fin (T) is dominant to a short dorsal fin. Cross a homozygous dominant shark with a heterozygous shark. Provide genotypic and phenotypic ratios. Slide 55 / Suppose in panda bears small ears (S) are dominant over big ears. You work at a zoo, and need to determine the genotype of your small eared panda. Explain how you could potentially determine the unknown genotype. Slide 56 / Explain how dihybrid crosses helped Mendel to develop his theory of independent assortment. Slide 57 / 116

20 56 Suppose in largemouth bass, green skin color (G) is dominant over olive (g) and broad stripe (B) is dominant over thin (b). Cross two bass that are heterozygous for both traits, and provide phenotypic ratios. Slide 58 / Suppose in spruce trees, long needles (L) are dominant over short needles (l) and thick bark (T) is dominant over thin (t). Cross a spruce tree heterozygous for needle length and homozygous dominant for bark thickness with a tree homozygous dominant for needle length and homozygous recessive for bark thickness. Provide genotypic and phenotypic ratios for offspring. Slide 59 / Use the rule of multiplication to determine the following: Suppose you cross two organisms with the genotype AaBbCc. What is the probability the offspring will have the same genotype? Slide 60 / 116

21 59 Use the rule of addition to determine the following: Suppose you cross two pea plants heterozygous for flower color (remember purple is dominant to white). What is the probability the offspring will be a homozygote? Slide 61 / Use the rules of multiplication and addition to determine the following: Suppose you cross two individuals with the following genotypes: AaBbCc x AaBbCc. What is the probability that you will produce an offspring with genotype AaBbCc or AAbbCc? Slide 62 / Provide one example in which the patterns of inheritance observed by Mendel would not apply Slide 63 / 116

22 62 How many phenotypes may exist for a trait that possesses two allele options? Slide 64 / Suppose Mendel s pea plants demonstrated incomplete dominance, with pink being the intermediate phenotype. What would the genotypic and phenotypic ratios have been in Mendel s F1 generation? Slide 65 / Suppose in crocodiles, the tooth length trait exhibits incomplete dominance. Cross a long toothed (L) crocodile with a short toothed crocodile. Provide ratios. Slide 66 / 116

23 65 In horses, red hair (R) is codominant with white hair (W). The codominant phenotype is a roan coat. Cross a red stallion with a roan mare. Provide ratios. Slide 67 / What is pleiotropy? Slide 68 / Explain the principle of polygenic inheritance. Slide 69 / 116

24 68 Why is height in humans considered to be a polygenic trait? Slide 70 / In humans there are three alleles for blood type: A, B and O. A and B are codominant, and O is recessive. Cross a type AB parent with an AO parent, provide potential genotypic and phenotypic ratios for offspring. Slide 71 / Refer to the question above. What is the probability that the parents would produce a child with type AB blood? Slide 72 / 116

25 71 Explain the principle of incomplete dominance. Slide 73 / In snapdragons, incomplete dominance results in a pink flower. Cross a red flower (R) with a pink flower. Provide ratios. Slide 74 / Explain the principle of codominance. Slide 75 / 116

26 74 Identify and explain the difference between codominance and incomplete dominance. Slide 76 / Explain why sickle cell anemia would be considered to be a pleiotropic trait. Slide 77 / Why is skin color in humans considered to be a polygenic trait? Slide 78 / 116

27 77 Consider a genetic mutation in which a single gene creates multiple effects in an afflicted individual. Would this be considered a pleiotropic or polygenic situation? Slide 79 / Suppose parents with type A blood had a child with type O blood. Explain how this situation could potentially occur. Slide 80 / In rabbits, coat color is a trait that demonstrates complete dominance, but has multiple alleles. Brown coat is dominant to all other alleles, Black coat is dominant to Gray coat. Cross a homozygous Brown rabbit with a heterozygous black rabbit. Provide ratios. Slide 81 / 116

28 80 Explain, using examples of non-mendelian inheritance, why Gregor Mendel may have had a more difficult time developing his rules for inheritance if his pea plants were not as straightforward in their hereditary patterns. Slide 82 / What genotype would an individual who suffers from a recessive inherited disease have to exhibit? Explain. Slide 83 / Would you be able to identify a carrier of a genetic disease by examining phenotype? Why or why not? Slide 84 / 116

29 83 Suppose two parents who were carriers of a recessive genetic disorder on a single allele decided to have children. What is the percent chance that their child could be born with the disorder? Slide 85 / Explain why consanguineous marriages may result in a higher rate of rare inherited disorders. Slide 86 / Can an individual be a carrier for a dominant genetic disorder? Explain your answer. Slide 87 / 116

30 86 What is a sex-linked disorder? Slide 88 / Suppose a female is a carrier for a sex-linked disorder that her husband does not have. What is the percent chance that she will have a child with the disorder? Does the gender of the child matter in this situation? Slide 89 / Suppose a mother with an X-linked dominant genetic disorder has a child with a male who does not exhibit the disorder. What is the likelihood that their child will have the disorder? Does the gender of the child matter in this situation? Slide 90 / 116

31 89 What is the role of a genetic counselor in the process of family planning? Slide 91 / Briefly explain the process of amniocentesis. Slide 92 / Explain, in terms of genotype versus phenotype, how ultrasounds and amniocentesis are used to predict the occurrence of genetic disorders. Slide 93 / 116

32 92 Define carrier, in terms of inherited diseases. Slide 94 / Suppose parents who are carriers of a recessive genetic disorder on a single allele decided to have a child with a parent who exhibits the same disorder. What is the percent chance that their child could be born with the disorder? Does this percentage change if they had a second child? Explain your answer. Slide 95 / Huntington s disease is a dominant genetic disorder. Would an individual heterozygous for the Huntington s allele demonstrate the disease? Explain your answer. Slide 96 / 116

33 95 Suppose a father, who is heterozygous for Huntington s disease, has a child with a mother who does not have the disease. What is the percent chance that the child will have the disease? Slide 97 / Identify the combination of sex chromosomes exhibited by a male and a female. Slide 98 / Why do males typically exhibit x-linked disorders more often than females? Slide 99 / 116

34 98 Suppose a father with an X-linked recessive disorder has a child with a woman who does not have the disorder. What is the percent chance that the child will have the disorder? Does gender matter in this situation? Slide 100 / Explain why, in relationship to sex chromosomes, most of the genes that are critical for survival are found on the X chromosome instead of the Y chromosome. Slide 101 / Briefly explain the process of chorionic villi sampling. What may be the advantage to this process over amniocentesis? Slide 102 / 116

35 101 What methods can be used to mitigate the symptoms of a child born with phenylketonuria? Slide 103 / Why are amniocentesis, CVS and fetoscopy generally only performed if the risk of genetic disease is deemed to be relatively high? Slide 104 / Why are pedigrees useful in studying genetic disorders? Slide 105 / 116

36 104 If two individuals in a pedigree do not have an autosomal recessive disorder, but one of their four children does have the selected disorder, what are the genotypes of the parents? How do you know? Slide 106 / Suppose you are using a pedigree to study a sexlinked recessive genetic disorder. If a female demonstrates this disorder, what is her genotype? What can you infer about her father s genotype? Slide 107 / Refer to the pedigree. Is the studied disorder a recessive or dominant disorder? How do you know? Slide 108 / 116

37 107 Refer to the pedigree. What can you infer about the genotype of individual II-1? How do you know? Slide 109 / Refer to the pedigree. Suppose this a sex-linked disorder. What can you infer about the genotype of individual I-1? Explain your answer. Slide 110 / When studying a pedigree, how can you tell if a trait is autosomal dominant or autosomal recessive? Slide 111 / 116

38 110 Suppose you are studying a pedigree for a genetic disorder that only shows up in male individuals. What details may you be able to infer about this disorder? Slide 112 / Suppose you are using a pedigree to study a sexlinked disorder. You come across a situation where a female has the disorder, but her father did not. Explain how this could occur. Slide 113 / Refer to the pedigree. Could this be an autosomal dominant disorder? Explain your answer. Slide 114 / 116

39 113 Refer to the pedigree. If this is an autosomal dominant disorder, what is the genotype of II-4? Slide 115 / Refer to the pedigree. If this is an autosomal recessive disorder, what is the genotype individual II-1? Slide 116 / 116