Learn on PengiAmplify Science (California) Grade 3Chapter 1: Why are wolves different from each other even though they are all the same species?

Sesson 2: Variation within Species

Key Idea.

Section 1

A Species Shares Similar Traits

Key Idea

A group of living things that are the same "kind" is called a species. For example, all pet cats belong to the same species, and all dandelions in a field belong to the same species. They are alike in many important ways.

Members of a species share many similar traits, or features. These shared traits help identify them as part of the same group. All tigers have stripes, and all robins have red chests. These common features show they belong together.

Section 2

Individuals Show Variation in Traits

Key Idea

Organisms in the same species, like all dogs, share many similar characteristics. These shared features help identify them as belonging to that group.

However, individuals in a species are not exactly alike. For any single trait, such as fur color, there can be many differences. Some dogs might have brown fur, while others have black or white fur.

Section 3

Scientists Find Patterns in Traits

Key Idea

Scientists study many organisms of the same species together. Looking at a whole group helps them see which traits are shared and how traits vary among individuals.

When they study a group, scientists look for patterns. A pattern shows which variations of a trait are common and which are rare. For example, in a classroom, having brown eyes might be a common trait, while having green eyes might be a rare trait.

Lesson overview

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Section 1

A Species Shares Similar Traits

Key Idea

A group of living things that are the same "kind" is called a species. For example, all pet cats belong to the same species, and all dandelions in a field belong to the same species. They are alike in many important ways.

Members of a species share many similar traits, or features. These shared traits help identify them as part of the same group. All tigers have stripes, and all robins have red chests. These common features show they belong together.

Section 2

Individuals Show Variation in Traits

Key Idea

Organisms in the same species, like all dogs, share many similar characteristics. These shared features help identify them as belonging to that group.

However, individuals in a species are not exactly alike. For any single trait, such as fur color, there can be many differences. Some dogs might have brown fur, while others have black or white fur.

Section 3

Scientists Find Patterns in Traits

Key Idea

Scientists study many organisms of the same species together. Looking at a whole group helps them see which traits are shared and how traits vary among individuals.

When they study a group, scientists look for patterns. A pattern shows which variations of a trait are common and which are rare. For example, in a classroom, having brown eyes might be a common trait, while having green eyes might be a rare trait.