Biology LEAP 2025 Comprehensive Review Exam Graded A+

Hypothesis - Tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation Variable - To vary or change Independent Variable - A manipulated variable in an experiment or study whose presence or degree determines the change in the dependent variable (thecause) Dependent Variable - The observed variable in an experiment or study whose changes are determined by the presence or degree of one or more independent variables (the effect) Control - A standard against which other conditions can be compared in a scientific experiment Basic Experiment Steps - 1. Plan the research including determining information sources, research subject selection, and ethical considerations for the proposed research and method, 2. Design the experiment concentrating on the system model and the interaction of independent and dependent variables, 3. Summarize a collection of observations to feature their commonality by suppressing details (descriptive statistics), 4. Reach consensus about what the observations tell us about the world we observe (statistical inference), 5. Document and present the results of the study. Qualitative Observation - Described by words or terms rather than numbers and including subjective descriptions in terms of variables such as color,shape, and smell; often recorded using terms, photographs, or drawingsQuantitative Observation - numerical values derived from counts or measurements of a variable;frequently require some kind of instrument use in recording. Organic Molecules - Organic compounds containing carbon and are found in all living things. Carbohydrates - Major source of QUICK energy and include sugars and starches Made up of carbon, hydrogen, and oxygen with a 2:1 ratio of hydrogen to oxygen Plants and animals use carbohydrates for maintaining structure within the cells Proteins - Nitrogen-containing compounds made up of chains of amino acids 20 amino acids can combine to form a great variety of protein molecules Can compose enzymes, hormones, antibodies, and structural components (also found in cell membranes) Lipids - HYDROPHOBIC water-insoluble (fats and oils) fatty acid building blocks Provide insulation and protection, store energy LONG TERM, found in cell membranes Nucleic Acids - Direct the instruction of proteins Stores the genetic information an organism receives from its parents Two types: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)Chloroplast - capture solar energy for photosynthesis (plant cells, some algae) Golgi Body - A structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell. Lysosomes - Cell organelle filled with enzymes needed to break down certain materials in the cell Mitochondria - An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. Nucleus - A part of the cell containing DNA and RNA and responsible for growth and reproduction Ribosomes - Site of protein synthesis Vacuole - Cell organelle that stores materials such as water, salts, proteins, and carbohydrates Cell membrane (plasma membrane) - Phospholipid bilayer that protects and encloses the cell. Controls transport Maintains homeostasis Cell wall - Rigid second layer that protects and encloses the cell (plant cells and some bacteria) Cytoplasm - A jellylike fluid inside the cell in which the organelles are suspended Rough Endoplasmic Reticulum - An endomembrane system covered with ribosomes where many proteins for transport are assembled.Smooth Endoplasmic Reticulum - An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down. Cytoskeleton - A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement