Overview
The document provides concise study notes for CSEC Biology, summarizing key topics, definitions, and essential concepts for exam preparation.
Introduction to Biology
- Biology is the study of living organisms and their interactions with the environment.
- Main branches include botany (plants), zoology (animals), and microbiology (microorganisms).
- Characteristics of living things include movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition (MRS GREN).
Cells and Cell Structure
- The cell is the basic unit of life.
- Major cell parts: nucleus (controls activities), cytoplasm (site of reactions), cell membrane (controls entry/exit), cell wall (plant cells only), chloroplasts (photosynthesis), and vacuole (storage).
- Animal and plant cells differ: plant cells have a cell wall, chloroplasts, and a large vacuole.
Nutrition
- Nutrition involves obtaining and using food for energy, growth, and repair.
- Types: autotropic (make own food, e.g., plants) and heterotrophic (eat other organisms, e.g., animals).
- Photosynthesis occurs in chloroplasts, using sunlight, water, and carbon dioxide to make glucose and oxygen.
Respiration
- Respiration is the release of energy from food.
- Aerobic respiration requires oxygen; anaerobic does not.
Transport in Organisms
- Plants have xylem (water transport) and phloem (food transport).
- The human circulatory system moves blood with oxygen, nutrients, and wastes around the body.
Excretion and Homeostasis
- Excretion is the removal of metabolic wastes.
- The kidneys filter blood to form urine, removing urea and excess water.
- Homeostasis maintains a stable internal environment.
Reproduction
- Asexual reproduction involves one parent and produces identical offspring.
- Sexual reproduction requires two parents and results in variation.
Key Terms & Definitions
- Biology — study of living things and their environments.
- Cell — basic structural and functional unit of life.
- Photosynthesis — process by which plants make food using sunlight.
- Respiration — process of releasing energy from food.
- Excretion — removal of waste products from metabolism.
- Homeostasis — maintenance of a stable internal environment.
Action Items / Next Steps
- Review MRS GREN characteristics for living things.
- Practice labeling plant and animal cell diagrams.
- Summarize differences between aerobic and anaerobic respiration.
- Prepare for a quiz on definitions and key biological processes.