1. Pages 62-63
Chapter 2
Life Cycles

2. Lesson 1 Vocabulary
Trait—a form of a characteristic that not all organisms have in common.
Heredity—the process by which traits are passed from parents to offspring.
Gene—a basic unit of heredity.

3. What is Heredity? All Sizes and Shapes
Page 64
What is
Heredity?
All Sizes and Shapes
All dogs belong to the same species. Fossils and genetic evidence show that all are descended from wolves.

4. Lesson 1—Traits (page 66)
All people have thumbs, but having a hitchhiker thumb is a trait.
Traits are passed on through heredity.

5. Lesson 1—Genes (page 67)
Genes carry instructions for how a living thing will grow and develop.
Each human has the same number and type of genes, but the instructions on the genes vary.
Different forms of genes cause people to have different traits!

6. Lesson 1—Genes (page 67) Genes work in pairs.
½ of your genes come from your mother
½ of your genes come from your father

7. Lesson 1—Traits (page 68)
Traits (such as eye color) are affected by genes alone.
Nurture (everything in your life) influences many traits. Example: hair color can be dyed and change.

8. Lesson 1—Traits (page 68) Name some traits: Eye color Rolling tongue
Hair color
Allergies
Widow’s peak
Longer 2nd toe
Cleft chin
Hitchhiker thumb

9. Lesson 1—Learned behaviors (69)
The people around you influence your traits, as well.
The language you speak and the words you use are learned from the people in your life.

10. Lesson 1—Not learned (69)
Some behaviors are not learned. Some animals hatch from eggs (never see their parents), but know exactly where to go and what to do to survive.

11. Lesson 1—Variations (page 70)
Genes affect characteristics such as height, shape, and color.
Some characteristics are affected by SEVERAL genes.
For example, eye colors can vary. They are not simply brown or blue.
Look at the variations in the Labrador retrievers.

12. Lesson 1—Variations (page 70)
You can’t change your eye color, BUT you can change some characteristics.
For example, how you eat and how much you exercise can determine how tall you grow or how much you weigh.

13. Review!!!!!
Trait—a form of a characteristic that not all organisms have in common.
Heredity—the process by which traits are passed from parents to offspring.
Gene—a basic unit of heredity.