Name



Name Class Date

11.1 The Work of Gregor Mendel

Lesson Objectives

Describe Mendel’s studies and conclusions about inheritance.

Describe what happens during segregation.

BUILD Vocabulary

A. The chart below shows key terms from the lesson with their definitions. Complete the chart by writing a strategy to help you remember the meaning of each term. One has been done for you.

|Term |Definition |How I’m Going to Remember the Meaning |

|Allele |Different form of a gene |An allele is an alternate form of a gene. |

|Fertilization |Process in which male and female gametes join to | |

| |produce a new cell | |

|Gamete |Cell used for reproduction; egg or sperm | |

|Gene |Information about an individual’s characteristics | |

| |that is passed from one generation to the next | |

|Hybrid |Offspring between parents with different traits | |

|Principle of dominance |Some alleles are dominant, and others are | |

| |recessive. | |

|Segregation |Separation of alleles during formation of sex | |

| |cells | |

|Trait |A specific characteristic of an individual | |

B. As you work through this lesson, you may find these terms in the activities. When you need to write a key term or a definition, highlight the term or the definition.

156

Name Class Date

The Experiments of Gregor Mendel

Dominance Mendel’s principle of dominance states that some alleles are dominant and others are recessive. An organism with a dominant allele will always show the dominant form of the trait. An organism will only express the recessive form of a trait when a dominant allele is not present.

In the space provided, fill in the genotype of the offspring. The first one is done for you.

|Dominant and Recessive Forms of Pea Plant Traits |

|Trait |Parent Plants (P Generation) |Offspring (F1 Generation) |

|Seed Color | |X | | |

|Seed Coat Color | |X | | |

|Pod Shape | |X | | |

Answer the questions. Circle the correct answer.

1. What is the dominant shape of a pea pod?

constricted smooth

2. What is the recessive color of a pea plant’s seed coat?

white gray

BUILD Connections

Not Two of Kind An analogy takes two things that seem to be different and shows how they can be similar. Visualize a hybrid car. Hybrid cars use two different sources of energy: gasoline and electricity.

1. A hybrid is a cross, or a mixture, of two things. What is crossed in hybrid cars?

2. Find a partner. Try to think of other things that are hybrids.

157

Name Class Date

BUILD Understanding

Two-Column Chart A two-column chart is a way to take notes about what you read. Copy the chart shown below in your notebook. Leave space for all the headings in the lesson. As you read the lesson, complete the chart. Write the main ideas in the left column. Use the names of the headings in the lesson. Then, list details and examples that go with that heading to the right column. An example has been done for you.

|Main Ideas |Details and Examples |

|The Experiments of |Mendel worked with garden peas. |

|Gregor Mendel | |

| | |

|_ | |

|_ | |

| | |

|_ | |

|_ | |

Inquiry Into Scientific Thinking

Classroom Variations Some traits are controlled by a single gene. Humans inherit genes from their parents. Children who exhibit a dominant allele such as freckles must receive the dominant allele from one of their parents.

Analyze and Conclude

The following table shows some Mendelian traits exhibited by Julia and her parents.

| |Julia’s Dad |Julia’s Mom |Julia |

|Freckles |yes |yes |yes |

|Cheek dimples |yes |no |yes |

|Free ear lobes |yes |no |no |

Use the table to answer the questions.

1. Which statement is true about Julia and her parents? Circle the correct answer.

A. They all have at least one dominant allele for freckles.

B. They all have at least one dominant allele for cheek dimples.

C. They all have at least one dominant allele for free ear lobes.

2. In the future, Julia will marry a man with freckles. However, her daughter will not have freckles. How is that possible?

158

-----------------------

Yellow YY

Green YY

Yellow YY

White gg

Gray GG

Gray

Constricted ss

Smooth SS

Smooth

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download