Description:

Students analyze the genetic characteristics of some hypothetical seeds. This assessment task is to be used after students have had instruction in Mendelian genetics.

This task is designed to take students approximately 15-20 minutes to complete.

Overall Task Content Area:

Life Science

Specific Knowledge Areas:

Genetics and Molecular Biology

Performance Expectations:

• formulating conclusions from investigational data
• applying scientific principles to develop explanations and solve new problems

National Science Education Standards:

12 A SI 1: Abilities necessary to do scientific inquiry: Grades 9-12
1.4 Formulate and revise scientific explanations and models using logic and evidence. Student inquiries should culminate in formulating an explanation or model. Models should be physical, conceptual, and mathematical. In the process of answering the questions, the students should engage in discussions and arguments that result in the revision of their explanations. These discussions should be based on scientific knowledge, the use of logic, and evidence from their investigation.

8 C LS 2: Reproduction and heredity: Grades 5-8
2.3 Every organism requires a set of instructions for specifying its traits. Heredity is the passage of these instructions from one generation to another.

2.4 Hereditary information is contained in genes, located in the chromosomes of each cell. Each gene carries a single unit of information. An inherited trait of an individual can be determined by one or by many genes, and a single gene can influence more than one trait. A human cell contains many thousands of different genes.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

National Council of Teachers of Mathematics:

DAP3: Develop and evaluate inferences and predictions that are based on data :
Grades 9-12 g. understand how sample statistics reflect the values of population parameters and use sampling distributions as the basis for informal inference

DAP4: Understand and apply basic concepts of probability :
Grades 9-12 j. understand the concepts of conditional probability and independent events
Grades 9-12 k. understand how to compute the probability of a compound event

PS2: Build new mathematical knowledge through problem solving:
Grades 9-12

CNX3: Recognize and apply mathematics in contexts outside of mathematics:
Grades 9-12

General Instructions to the Teacher:

The purpose of this task is for students to use their knowledge and understanding of Mendelian genetics to analyze the genetic characteristics of some hypothetical seeds. Students should work alone to read the initial scenario and answer the four questions which follow.

You may want to remind students that if they use symbols in their answers (e.g. TT, Tt, tt), they must provide a key explaining how their symbols are being used. For example, an acceptable key would look like:

T	=	tall allele
t	=	short allele
TT	=	pure tall
Tt	=	heterozygous tall
Tt	=	pure short

Skills used in this task include (primarily) interpreting data and predicting, and (secondarily) communicating and classifying.

This task is designed to take most students 15-20 minutes to complete.

Materials for Ajax Seed Company:

At this station students should have:

Only the individual student answer sheets are required.

Advance Preparation:

None required.

Safety:

• Be careful.

• Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.