Block

In

Draw a pedigree chart for your family (grandparents, aunts, uncles, immediate family)

Block

Through

Patterns of inheritance A and B

OUT

C-note 492-495

Patterns of InheritancePatterns of Inheritance

Open your book to page 427.

In this activity, you will begin to model how genetic information is passed from one generation to the next.

Process and Procedures

Part A. Inheritance of One traitYou will use 2 colors of beans to represent the genetic information that contributes to the trait for straight or floppy ears in rabbits.1. Without looking, each person selects two beans from the cup.

2. Record the color of your beans. Also, note whether your pair is homozygous or heterozygous.– Homozygous-beans are same in color– Heterozygous-beans are different colors

3. Each person places both of their beans in their hands and shakes them up and selects 1 bean without looking.– Each parent contributes only half of their

own genetic information to each offspring. Parents do not know what half they give.

Parent 1 Parent 2

Offspring

4. Add this bean to the one your partner selected.

5. Record the color of the 2 beans in the new combination (offspring). Indicate whether the new pair is homozygous or heterozygous.

6. Use the color key provided and answer the following questions.

Color key

A. What was your 1st condition?

B. What was your partners condition?

C. What was your new (offspring) condition?

Brown Brown Floppy ear

White White Straight ear

Brown

White

White

Brown

Straight ear

7. As a part of a class discussion, use the key once again and the shared results of the class to consider the following:

A. Did 1 bean color have a greater influence in determining the ear trait than the other bean color? Explain

B. Write the phenotype and genotype for your combination of beans, your partners, and your offspring.– Phenotype- Straight ear– Genotype- SS,Ss – Phenotype - Floppy ear– Genotype - ss

Phenotype ME Partner Offspring

Straight Straight Floppy

Genotype ME Partner Offspring

Ss Ss ss

7c. Use genetic terminology to describe what we did during this activity.

– List the characteristics you share with your parents.

• For example; I have my dad’s eye shape

Part B Inheritance of Two Traits

Today, you will work with your partner to study the inheritance of two traits together; ear type and sex in rabbits

1. Examine the tables in the Need to know bow titled “Following the Inheritance of Two Traits”.– Floppy ears or straight ears– Male rabbits or female rabbits

2. Based on the results, what conclusions can you draw about these two traits?

3. Male rabbits that had straight ears were mated with female rabbits with floppy ears. Calculate the data for sex and ear type as percentages.

Percntage with trait=[(#with trait)÷(total #offspring)] X 100

Male % Female %

Floppy % Straight %

4. Discuss the following with your table and record answers.

A. What overall conclusions can you draw about the inheritance of straight ears versus floppy ears?

B. Do you think the type of ear a rabbit is born with is affected by whether a rabbit is female or male? Explain

Analysis questions

2. Restate the following accurately, One out of every two offspring that result from a cross between parents with the genotypes Hh and hh definitely will have Huntington’s disease.

3. Two healthy individuals marry and produce three children. The first two are healthy. But the third is born with cystic fibrosis alleles. What can you conclude about the genotypes of the other people in the family?

5. In cocker spaniels, black B is dominant over red b. Solid color S is dominant over white spotting s. A red male was mated to a black-and-white female. They had five puppies, as follows: one black, one red, one black and white, and two red-and-white.A. What genetic principle explains the phenotypes of these offspring?B. Write a one or two paragraphs to describe how that principle worked in this cocker spaniel family. Include the following terms; gene, phenotype, dominant trait, recessive trait, chromosome, allele, genotype