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AGR 3303 (3 credits) University of Florida - Fort Lauderdale  |
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| Below is exam #1 for 1996, Mendelian genetics |
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AGR 3303 - Genetics 26 Sep 1996 University of Florida - Fort Lauderdale Exam #1: PARTICULATE GENETICS Student name_______________________________ Multiple choice 60 pts. Please read these carefully. One and only one response (a, b, c, d, or e) completely and correctly answers the question, or completes the statement. Circle the appropriate response and turn in this exam. Make sure your circle is unambiguous. Take time to relax. (Suggestion: put the problem into gene symbols, if that helps you to visualize the problem and its solution.) 1. A genetics class grew 200 corn seedlings, which were expected to segregate in a 3:1 Mendelian ratio. The observed numbers of seedlings were 161 green:39 albino. Based on the tabular probability value from chi square (P=0.072), we conclude that: a. the null hypothesis cannot be accepted b. Mendelian genetics does not adequately explain the results c. the genes are not assorting independently d. the genes must be linked e. none of the above 2. Color of chickens is determined by interacting loci: AA or Aa give white, aaBB or aaBb give colored, and aabb produces white. What are the phenotypic frequencies of the offspring from a cross between a heterozygous white chicken (Aabb) and a heterozygous colored (aaBb) chicken? a. 15 white : 1 colored b. 13 white : 3 colored c. 3 white : 1 colored d. 9 white : 7 colored e. none of the above 3. If an organism has 2n=8, then a. during mitosis there will be 8 chromosomes going to each pole b. during meiosis there will be 4 chromosomes going to each pole c. during meiosis, there will be 4 pairs of chromosomes d. all of the above e. none of the above 4. Darwin's theory, presented in The origin of species, explained what? a. the theory of heredity b. how species could change c. the origin of mutations d. the basis of variation e. none of the above 5. The inheritance of human ABO blood antigens are explained by: a. dominance, epistasis, and polygenes b. dominance, codominance, and polygenes c. dominance, codominance, and multiple alleles d. dominance, incomplete dominance, and multiple alleles e. dominance, codominance, incomplete dominance, and multiple alleles 6. A baby-switching case involves an infant with type AB blood. Which is true? a. The woman with type A blood could not be the mother. b. The woman with type O blood could not be the mother. c. The woman with type B blood could not be the mother. d. The woman with type AB blood could not be the mother. e. Any of the four women could be the mother 7. The haploid chromosome number of the horse is n=16. How many autosomes are there in the zygote? a. 15 b. 16 c. 28 d. 30 e. 32 8. A man discovers that his mother has Huntington's disease, which is caused by a dominant autosomal allele. What is the chance that he will have the disease? a. 0% b. 25% c. 50% d. 75% e. 100% 9. In contrast to mitosis, in meiosis there is/are: a. identical daughter cells b. reduced chromosome number c. two daughter cells d. all of the above e. none of the above 10. A mother has blood type A and a father has blood type B. Their first child has blood type O. What is the chance that their second child will have blood type O? a. 100% b. 75% c. 50% d. 25% e. 0% 11. What is true for human sex chromosomes? a. the man always inherits his X from his father's mother b. the woman always inherits her X from her mother's father c. the man always inherits his Y from his father's mother d. all of the above e. none of the above 12. Seed capsule shape in the weed "Shepherd's purse" is controlled by two independent genes C and D. The double recessive condition (ccdd) results in ovoid capsule shape. A dominant allele at either locus results in triangular capsule shape. What phenotypic ratio would result from self-pollinating a double heterozygote (CcDd)? a. 1 triangular:15 ovoid b. 1 triangular:3 ovoid c. 9 triangular:7 ovoid d. 12 triangular:4 ovoid e. 15 triangular:1 ovoid 13. Individuals in a population of organisms differ from one another, due to both genotypic and environmental causes. Because it is difficult to assign those differences to the effect of any individual gene, scientists study such populations by a measure of dispersion called: a. the range b. the mean c. the variance d. chi-square e. null hypothesis 14. Assume that each of four genes determines a different trait, and each gene has two alleles, one of which is dominant, and the other recessive. In a diploid organism, how many possible genotypes are there? a. 8 b. 9 c. 16 d. 27 e. 81 15. Duchenne muscular dystrophy in humans is a rare, sex-linked, recessive trait. A woman has two biological sons, #1 and #2. The sons have the same father. Son #1 has Duchenne muscular dystrophy. Which value most closely estimates the chance that son #2 has the same condition? a. 100% b. 75% c. 50% d. 25% e. 0% Matching 24 pts. In each of the following 11 spaces, insert the correct word or phrase from the list at the bottom of the page. 16. Recessive alleles are expressed only when they are in this condition:
__________________________________. 17. If the chromosome number is not an exact multiple of the haploid set, the individual is considered to be: ________________________________________. 18. There is one of these for each chromosome:
__________________________________. 19. DNA synthesis occurs during which stage of the cell cycle?
__________________________________. 20. The type of chromosomes which are similar and can pair during meiosis:
__________________________________. 21. When genes interact in a nonreciprocal manner, this is called:
__________________________________. 22. Homologous ("similar") chromosomes do this, only in meiosis:
__________________________________. 23. A form of a gene:
__________________________________. 24. A haploid cell resulting from meiosis, and which can undergo fertilization, is a:
__________________________________. 25. The ratio of genotypic variance divided by phenotypic variance
__________________________________. 26. What results from polygenic inheritance
__________________________________. 27. This condition is the only human autosomal trisomic in which most individuals survive to adulthood:
__________________________________. Short answer 16 pts. 28. List Mendel's four postulates: 4 pts. a. _____________________________________________________________ b. _____________________________________________________________ c. _____________________________________________________________ d. _____________________________________________________________
29. List and briefly describe at least two genetic reasons that genetic data would 6 pts. not conform to expected Mendelian ratios (e.g., 3:1 and 9:3:3:1). [Only the best two will be graded.]
a. __________________________________
_____________________________________________________________
_____________________________________________________________
b. __________________________________
_____________________________________________________________
_____________________________________________________________
c. __________________________________
_____________________________________________________________
_____________________________________________________________ 30. Define a gene: 2 pts. ____________________________________________________________________
____________________________________________________________________
31. On the reverse side of this sheet, draw a plant cell and correctly locate and 4 pts. label the major structures, making sure to include all structures involved with genetic mechanisms. |
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