 |
|
|
||||
|
|
|
|
||
|
AGR 3303 (3 credits) University of Florida - Fort Lauderdale  |
|
||||||||
|
||||||||
|
||||||||
| Below is exam #1 part B, for 1996, Mendelian
genetics |
||||||||
|
||||||||
|
AGR 3303 - Genetics 17 Oct 1996 University of Florida - Fort Lauderdale Exam #1B: PARTICULATE GENETICS Multiple choice 24 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. Assume that each of three 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 phenotypes are there? a. 8 b. 9 c. 16 d. 27 e. 81 2. 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 crossing a double heterozygote (CcDd) with a double homozygous tester (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 3. What is true for human sex chromosomes? a. the man always passes his X chromosome to his daughter b. the man always passes his Y chromosome to his son c. the woman always passes an X chromosome to her son d. all of the above e. none of the above 4. If an organism has 2n=46, then a. during meiosis there will be 46 chromosomes going to each pole b. during meiosis, there will be 23 pairs of chromosomes c. during mitosis there will be 23 chromosomes going to each pole d. all of the above e. none of the above 5. In contrast to Mendel's categorical approach to studying genetic variability, the variance is used in certain situations because: a. with polygenes, the effect of an individual gene cannot be separately distinguished b. variance is a measure of dispersion which can be modeled in an additive manner c. phenotypic variance can be partitioned into genetic, environmental, and genetic X environmental sources d. all of the above e. none of the above 6. A crossing experiment results in a phenotypic ratio of 9:3:3:1. The simplest explanation that could adequately explain this result is: a. There are two genes, each gene with a dominant allele and a recessive allele b. There is one gene with four alleles c. There are three genes with linkage d. There are two genes, each gene with a dominant allele and a recessive allele, and at least one gene is linked on the sex chromosome e. None of these hypotheses can explain the results 7. Flower color in pea is determined by interacting loci: A_ B_ give purple; while A_bb, aaB_, and aabb give white. What are the phenotypic frequencies of the offspring from a cross between two pea plants, with genotypes Aabb and aaBb? a. 15 white : 1 purple b. 13 white : 3 purple c. 3 white : 1 purple d. 9 white : 7 purple e. none of the above 8. A paternity case involves an infant with type O blood. Which is true? a. The man with type A blood could not be the father. b. The man with type O blood could not be the father. c. The man with type B blood could not be the father. d. The man with type AB blood could not be the father. e. Any of the four men could be the father |
|
|||
| (return to top) | |||