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Explore the concept of traits and heredity through a genetics lab, where you will analyze physical features, learn about dominant and recessive alleles, and conduct surveys to understand trait prevalence.
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Welcome to Science 2/9 • Turn in Mitosis v. Meiosis Lab. On your paper, record as many physical features as you can for each organism. • Today’s Schedule • 1. Question of the Day • 2. Ch. 3 Section 1: Genetics
Question of the Day • Migration and hibernation are two different types of behavioral adaptations. • What do both of these processes have in common? • A. They help the organism produce food. • B. They help the organism produce energy. • C. They help the organism change the environment. • D. They help the organism adjust to changes in the environment.
Why do organisms look like that? Traits- the physical characteristics that make up an organism . Heredity- the passing of traits from parents to offspring. Genetics- the scientific study of heredity. Organisms inherit their traits from their parents.
Who was Mendel? • The “Father” of Genetics • Studied peas and observed how peas passed on their traits to offspring.
Mendel’s Experiments • Purebred- an organism that always produces offspring with the same form of a trait as the parent. • Remember, Mendel wanted to know why pea plants had certain traits!!! • Mendel crossed purebred tall pea plants with purebred short pea plants.
So, why do organisms show certain traits over others? • In sexual reproduction a female contributes 1 factor and male contributes 1 factor. • The dominant factor will mask the other factor.
So, why do organisms show certain traits over others? • Genes- the factors that control traits. • Alleles- different form of a gene. • Example: (Gene = height) (Alleles= tall & short) (Gene = hair color) (Alleles= dark & light) The dominant allele controls the inheritance of traits. The recessive allele will be masked or covered up.
Hybrids • Hybrid- is the crossing of two things to make one. • For hybrid organisms the dominant allele will always mask or cover up the recessive allele.
A closer look. • Heredity and Traits • dominant human traits • more human traits
Welcome to Science 2/10 • Answer both Questions of the Day on your paper. • One of the most beautiful and common butterflies in our area is the monarch butterfly. Due to the diet of monarch caterpillars, the butterflies develop a taste that is unpleasant. Another species, called the viceroy butterfly, does not produce an unpleasant taste, but has evolved a color pattern similar to the monarch. Both species have different adaptations that help them survive. 1. Which type of adaptation probably help the monarch survive? A. Migration B. camouflage C. unpleasant taste D. imitating another species 2. Which type of adaptation probably helps the viceroy survive? A. Migration B. camouflage C. unpleasant taste D. imitating another species
Skills Lab • Open your book to page 86-87 • Objective: Explore how greatly traits can vary in a group of people—your classmates. • Problem: Are traits controlled by dominant alleles more common than traits controlled by recessive alleles? • 1. Follow the procedure. • 2. Complete the entire lab sheet. • 3. Lab due at the end of class.
Skills Lab Part 1 • Problem:Are traits controlled by dominant alleles more common than traits controlled by recessive alleles? • Write down your hypothesis now.
Skills Lab Part 2 • Work with a partner to determine which traits you have. Circle your traits in the data table.
Skills Lab Part 3 • You will now survey 7 more students in your class and record your findings in the data table below.
Skills Lab Part 4 • Look at the circle of traits on page 87. All the traits listed in your data table appear in the circle. Place the eraser end of your pencil on the trait in the central circle that applies to you-either free ear lobes or attached ear lobes. • 6. Look at the two traits touching the space your eraser is on. Move your eraser onto the next description that applies to you. Continue using your eraser to trace your traits until you reach a number on the outside rim of the circle. Write that number in the box.
Skills Lab Part 5 • Answer the analyze and conclude questions.