Life Cycles & Traits, Part II: Interdependent Relationships in Ecosystems
Unit description: In Part I, students explore the similarities and differences between plant and animal life cycles, how traits are inherited from parents, and how the environment can influence the inheritance of those traits. In Part II, students study how the organisms in an ecosystem impact and depend on each other for survival.
Download the complete Grade 3 Science Unit 3 framework to customize for your own planning.
Essential Questions and Big Ideas
Part I: Life Cycles and Traits
- Do living things grow and develop the same?
- Reproduction is essential to the continued existence of every kind of organism. Plants and animals have unique and diverse life cycles. (3-LS1-1)
- Why do living things look similar to their parents?
- Many characteristics of organisms are inherited from their parents. (3-LS3-1)
- Different organisms vary in how they look and function because they have different inherited information. (3-LS3-1)
- Can the environment change the way a plant or animal looks?
- Other characteristics result from individuals’ interactions with the environment, which can range from diet to learning. (3-LS3-2)
- Some characteristics result from the interactions of both inheritance and the effect of the environment. (3-LS3-2)
- The environment also affects the traits that an organism develops. (3-LS3-2)
- Why do some animals or plants survive better than others?
- Sometimes the differences in characteristics between individuals of the same species provide advantages in surviving, finding mates, and reproducing. (3-LS4-2)
Part II: Interdependence in Ecosystems
- How do plants and animals help each other?
- Being part of a group helps some animals obtain food, defend themselves, and survive. Groups may serve different functions and vary dramatically in size. (3-LS2-1)
- How do we know what plants and animals looked like many years ago?
- Some kinds of plants and animals that once lived on Earth are no longer found anywhere. (3-LS4-1)
- Fossils provide evidence about the types of organisms that lived long ago and also about the nature of their environments. (3-LS4-1)
- What makes some living things survive better than others?
- For any particular environment, some kinds of organisms survive well, some survive less well, and some cannot survive at all. (3-LS4-3)
- What happens to plants and animals when the environment changes?
- Populations live in a variety of habitats, and change in those habitats affects the organisms living there. (3-LS4-4)
- When the environment changes in ways that affect a place’s physical characteristics, temperature, or availability of resources, some organisms survive and reproduce, others move to new locations, yet others move into the transformed environment, and some die. (secondary to 3-LS4-4)
Prerequisite Skills/Science & Engineering Practices
Develop models to describe concepts, analyze and interpret data to provide evidence, use evidence to construct and/or support an explanation, make a claim about the merit of a solution to a problem.