unit 3 study guide 7th life science

2 min read 01-02-2025

This study guide covers the key concepts from Unit 3 of your 7th-grade Life Science curriculum. Remember to consult your textbook, class notes, and any other provided materials for a comprehensive review. Good luck with your studies!

Cells: The Basic Units of Life

What are Cells?

Define a cell and explain its importance as the basic unit of life.
Differentiate between prokaryotic and eukaryotic cells. What are the key differences in their structure and complexity? Provide examples of organisms with each type of cell.
Describe the functions of the major organelles found in eukaryotic cells (cell membrane, cell wall, cytoplasm, nucleus, mitochondria, chloroplasts, vacuoles, ribosomes). Be able to draw a simple diagram of a plant and animal cell, labeling these organelles.
Explain the concept of cell specialization and provide examples of specialized cells and their functions in multicellular organisms.

Cell Processes

Define diffusion and osmosis. How do these processes contribute to the movement of substances across cell membranes?
Explain the role of active transport in moving molecules across cell membranes. How does it differ from passive transport (diffusion and osmosis)?
Describe the processes of photosynthesis and cellular respiration. What are the inputs and outputs of each process? How are they related?

Levels of Organization in Living Things

From Cells to Organisms

Describe the levels of organization in living things, starting from cells and progressing to tissues, organs, organ systems, and organisms. Provide examples for each level.
Explain how cells work together to form tissues, tissues form organs, organs form organ systems, and organ systems work together to form a complete organism. Use specific examples to illustrate these relationships.

Organ Systems

Describe the major organ systems of the human body (digestive, respiratory, circulatory, excretory, nervous, skeletal, muscular). For each system, list the main organs involved and their functions.
Explain how different organ systems interact and depend on each other to maintain homeostasis (a stable internal environment).

Genetics and Heredity

(This section might or might not be included in Unit 3, depending on your curriculum. Check your syllabus.)

Basic Genetics

Define the terms gene, allele, chromosome, DNA, and genotype and phenotype.
Explain the concepts of dominant and recessive traits. Use Punnett squares to predict the probability of inheriting certain traits.
Describe the process of meiosis and its role in sexual reproduction. How does meiosis contribute to genetic variation?

Practice Questions

To solidify your understanding, try answering these questions:

What is the difference between plant and animal cells?
Describe the process of photosynthesis. What organisms perform photosynthesis?
Explain how the circulatory and respiratory systems work together.
What is the role of the nervous system?
If a trait is recessive, what must be true about the alleles for that trait in an organism that expresses the trait?

This study guide provides a framework for your review. Remember to refer back to your course materials for specific details and examples. Good luck on your Unit 3 assessment!