TEKS Addressed: 7.1A, 7.1B, 7.2A, 7.2C, 7.2E, 7.3A, 7.3B, 7.3C, 7.3D, 7.4A, 7.4B, 7.11A, 7.11B, 7.11C, 7.12A, 7.12C

Introduction

This unit bundles Student Expectations that address variation of populations and species, traits inherited through gradual processes over many generations, and the complementary nature of structure and function. Variation of traits within a population enhances the survival of the species because some individuals are better adapted to survive conditions within the environment.

Prior to this Unit

• Grade 6

  • 6.12D – Identify the basic characteristics of organisms, including prokaryotic or eukaryotic, unicellular or multicellular, autotrophic or heterotrophic, and mode of reproduction, that further classify them in the currently recognized Kingdoms.

• Grade 7

  • 7.12C – Recognize levels of organization in plants and animals, including cells, tissues, organs, organ systems, and organisms.

  • 7.12D – Differentiate between structure and function in plant and animal cell organelles, including cell membrane, cell wall, nucleus, cytoplasm, mitochondrion, chloroplast, and vacuole.

  • 7.14A – Define heredity as the passage of genetic instructions from one generation to the next generation.

  • 7.14B – Compare the results of uniform or diverse offspring from sexual reproduction or asexual reproduction.

  • 7.14C – Recognize that inherited traits of individuals are governed in the genetic material found in the genes within chromosomes in the nucleus.

During this Unit

Students use scientific practices and tools to investigate and explain how internal structures of organisms have adaptations that allow specific functions to occur. They explain variation within a population or species by comparing external features, behaviors, or physiology of organisms that enhance their survival. Students also identify changes in genetic traits that have occurred over several generations through natural selection and selective breeding. Moreover, students examine organisms or their structures and use dichotomous keys for identification. They also continue to identify levels of organization in the context of this unit. Additionally, students communicate and discuss their observations and record and organize data in their notebooks. Students continue to demonstrate safe practices as outlined in the Texas Education Agency-approved safety standards and consider environmentally appropriate and ethical practices with resources during investigations.

After this Unit

Students will study change in organisms over time and classification of organisms in greater depth in High School Biology.