Download Name: Date: Teacher: Class/Period: 1)

Name:
Teacher:
1)
Date:
Class/Period:
Please use the space below to write your response(s) to the writing assignment provided by your
teacher. If there are multiple tasks to the question, please clearly label the number or letter of each
task in the column to the left of your answers. If you need additional pages for your response, your
teacher can provide them.
Please write the name of the writing assignment here: _____________________________________
Task
Answer Key
1) Scoring Criteria:
A 4-point response will include, but is not limited to, the following points:
x
Allele designations and genotype labels for each phenotype:
T = allele for exhibiting tylosis
t = allele for not exhibiting tylosis
TT or Tt = individuals exhibiting tylosis
tt = individuals not exhibing tylosis
Note: The student may use alternate, clearly labeled designations.
x
Determination of Ryan’s genotype and whether he has tylosis: Ryan’s genotype is
Tt and he has tylosis.
Explanation of the answer: Kate (Ryan’s wife) does not have tylosis, but Bryce (Ryan
and Kate’s son) has tylosis. Kate does not have a T allele because she does not have
tylosis, so Bryce must have received a T allele from Ryan. Therefore, Ryan must have
tylosis. Because Erin does not have tylosis, she must have received a t allele from both
Ryan and Kate. Therefore, Ryan’s genotype is Tt.
Optional Punnett square: Kate (tt) x Ryan (Tt)
x
Diagram of the pedigree for this family indicating each individual’s genotype and
phenotype for tylosis: The response must include an accurately diagrammed
pedigree. Each named individual’s genotype must be noted, and circles and squares for
individuals exhibiting tylosis must be filled in accordingly to reflect phenotype.
x
Determination of the probability that Erin and Liam’s third child will have tylosis:
50%
Explanation: Because Erin does not have tylosis, she must have the genotype tt.
Because Liam has tylosis, he must have the genotype TT or Tt. Liam must have the
genotype Tt because his son, Kyle, has tylosis, but his daughter, Jana, does not. Liam
must carry only one copy of the dominant gene, otherwise all of his children would have
tylosis. The Punnett square shows that there is 50% chance for any of Erin and Liam’s
children to have the genotype Tt and have tylosis.
Punnett Square: Erin (tt) x Liam (Tt)
Rubric:
4
A response at this level provides evidence of thorough knowledge and
understanding of the subject matter.
 The content of the response is correct and thorough, with no significant errors.
 The response contains elaboration and/or detail that demonstrates insight into
scientific concepts and principles, and contains no misconceptions.
 The explanation in the response is clear and is enhanced by correct use of
appropriate scientific terminology to communicate understanding.
3
A response at this level provides evidence of competent knowledge and
understanding of the subject matter.
 The content of the response is generally correct and complete.
 The response contains some elaboration and/or detail that demonstrates sufficient
understanding of scientific concepts and principles, and it may contain a few minor
misconceptions.
 The explanation in the response is mostly clear and is supported by some correct
use of appropriate scientific terminology to communicate understanding.
2
A response at this level provides evidence of basic knowledge and understanding
of the subject matter.
 The content of the response is partially correct, and it may be incomplete.
 The response contains a little elaboration and/or detail to demonstrate some
understanding of scientific concepts and principles, but it may contain some
significant misconceptions.
 The explanation in the response is sometimes clear and sometimes demonstrates
correct use of appropriate scientific terminology to communicate understanding.
1
A response at this level provides evidence of minimal knowledge and
understanding of the subject matter.
 The content of the response is mostly incorrect, and it is incomplete.
 The response contains little or no elaboration or detail to demonstrate understanding
of scientific concepts and principles, and it contains evidence of significant
misconceptions.
 The explanation in the response is mostly unclear and demonstrates little or no
correct use of appropriate scientific terminology to communicate understanding.
0
A response at this level is not scorable. The response is off-topic, blank, hostile, or
otherwise not scorable.