Biologia

Portfolio 3 Page 1

UNIT 3 Genetics and Biotechnology
Chapter 11 Introduction to Genetics

SESSION 1 11.1 The work of Gregor Mendel
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 therecessive 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 Seed Color Parent Plants (P Generation)
Green YY

Offspring (F1 Generation)
Yellow YY

Yellow YY

X

Seed Coat Color

White gg

X

Gray GG

Gray

Pod ShapeConstricted ss

Smooth SS

Smooth

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 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. 1 CIDEB

Portfolio 3 Page 2

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 suchas 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 Freckles Cheek dimples Free ear lobes yes yes yes Julia’s Mom yes no no Julia yes yes no

Use the table to answer the questions. 1. Which statement is true about Julia and her parents? Circle the correctanswer. 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?

2 CIDEB

Portfolio 3 Page 3

SESSION 2

Section Assessment 11.11- a. Review. What did Mendel conclude determines biological inheritance?

____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________
b. Explain.What are dominant and recessive alleles?

____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________
c. Apply Concepts. Why were true- breedingpea plants important for Mendel’s experiments?

____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________
2- a. Review. What is segregation?____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________ ____________________________________________________________

____________
b. Explain What happens to alleles between the P generation and the F2 generation?...