This study guide covers the key concepts typically found in a 7th-grade life science Unit 3. Remember to check your specific textbook and class notes for details relevant to your curriculum. This guide provides a broad overview and may not cover every single detail.
Cells and Their Functions
What are Cells?
- Definition: The basic unit of life; all living things are made of cells.
- Types of Cells: Understand the difference between prokaryotic (lacking a nucleus) and eukaryotic (possessing a nucleus) cells. Be able to identify examples of each. Focus on the key differences in their structures and functions.
- Cell Organelles: Learn the functions of major organelles such as the nucleus, mitochondria, chloroplasts (plant cells only), cell membrane, cell wall (plant cells only), ribosomes, and vacuoles. Know how each organelle contributes to the overall function of the cell.
- Cell Processes: Familiarize yourself with processes like cellular respiration (energy production), photosynthesis (plant cells only), and protein synthesis.
Cell Specialization
- Definition: How cells develop to perform specific tasks within a multicellular organism.
- Examples: Learn examples of specialized cells and their functions (e.g., muscle cells, nerve cells, blood cells, root hair cells). Understanding how specialized cells work together to form tissues and organs is crucial.
- Tissues, Organs, and Organ Systems: Understand the hierarchical organization of cells into tissues, organs, and organ systems. Be able to give examples of each level of organization.
Photosynthesis and Respiration
Photosynthesis
- Definition: The process by which plants convert light energy into chemical energy (glucose).
- Equation: Understand and be able to write the balanced chemical equation for photosynthesis.
- Factors Affecting Photosynthesis: Know how factors like light intensity, carbon dioxide concentration, and temperature influence the rate of photosynthesis.
- Importance: Recognize the critical role photosynthesis plays in providing energy for most ecosystems.
Cellular Respiration
- Definition: The process by which cells break down glucose to release energy (ATP).
- Equation: Understand and be able to write the balanced chemical equation for cellular respiration (aerobic respiration).
- Types of Respiration: Differentiate between aerobic (requiring oxygen) and anaerobic (not requiring oxygen) respiration.
- Importance: Recognize the role of cellular respiration in providing energy for all living things.
Genetics and Heredity
DNA and Genes
- Definition: Understand the basic structure and function of DNA as the genetic material. Know the role of genes as units of heredity.
- Chromosomes: Learn about chromosomes and their role in carrying genetic information.
- Inheritance: Understand how traits are passed from parents to offspring.
Mendelian Genetics
- Basic Principles: Understand Mendel's laws of inheritance (segregation and independent assortment).
- Dominant and Recessive Alleles: Learn the concepts of dominant and recessive alleles and how they determine the expression of traits.
- Genotype and Phenotype: Distinguish between genotype (genetic makeup) and phenotype (observable traits).
- Punnett Squares: Practice using Punnett squares to predict the probability of offspring inheriting specific traits.
Evolution and Natural Selection
- Evolution: Understand evolution as a change in the heritable characteristics of biological populations over successive generations.
- Natural Selection: Explain the mechanism of natural selection and how it drives evolution. Understand the concepts of variation, adaptation, and survival of the fittest.
- Evidence for Evolution: Be familiar with different types of evidence that support the theory of evolution (e.g., fossil record, comparative anatomy, molecular biology).
This study guide provides a framework. Remember to review your class materials and focus on the specific topics emphasized by your teacher. Good luck with your studies!
