MS-LS3-1 Heredity: Inheritance and Variation of Traits
Students who demonstrate understanding can:
MS-LS3-1.
Develop and use a model to describe why structural changes to genes (mutations) located on
chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the
structure and function of the organism.[Clarification Statement: Emphasis is on conceptual
understanding that changes in genetic material may result in making different proteins.] [Assessment
Boundary: Assessment does not include specific changes at the molecular level, mechanisms for protein
synthesis, or specific types of mutations.]
The performance expectation above was developed using t he following elements from the NRC document A Framework for K-12 Science Education:
Science and Engineering Practices
Developing and Using Models
Modeling in 6–8 builds on K–5 experiences
and progresses to developing, using, and
revising models to describe, test, and
predict more abstract phenomena and
design systems.
Develop and use a model to describe
phenomena.
Disciplinary Core Ideas
LS3.A: Inheritance of Traits
Genes are located in the chromosomes
of cells, with each chromosome pair
containing two variants of each of many
distinct genes. Each distinct gene
chiefly controls the production of
specific proteins, which in turn affects
the traits of the individual. Changes
(mutations) to genes can result in
changes to proteins, which can affect
the structures and functions of the
organism and thereby change traits.
LS3.B: Variation of Traits
In addition to variations that arise from
sexual reproduction, genetic
information can be altered because of
mutations. Though rare, mutations may
result in changes to the structure and
function of proteins. Some changes are
beneficial, others harmful, and some
neutral to the organism.
Crosscutting Concepts
Structure and Function
Complex and microscopic
structures and systems can
be visualized, modeled, and
used to describe how their
function depends on the
shapes, composition, and
relationships among its
parts, therefore complex
natural structures/systems
can be analyzed to
determine how they
function.
Observable features of the student performance by the end of the course:
1
Components of the model
a
Students develop a model in which they identify the relevant components for making sense of a
given phenomenon involving the relationship between mutations and the effects on the organism,
including:
i. Genes, located on chromosomes.
ii. Proteins.
iii. Traits of organisms.
2
Relationships
a
In their model, students describe* the relationships between components, including:
i. Every gene has a certain structure, which determines the structure of a specific set of
proteins.
ii. Protein structure influences protein function (e.g., the structure of some blood proteins allows
them to attach to oxygen, the structure of a normal digestive protein allows it break down
particular food molecules).
iii. Observable organism traits (e.g., structural, functional, behavioral) result from the activity of
proteins.
3
Connections
a
Students use the model to describe* that structural changes to genes (i.e., mutations) may result in
observable effects at the level of the organism, including why structural changes to genes:
i. May affect protein structure and function.
June 2015
Page 1 of 4
