SCIENCE EXAM REVIEW

Unit 1 - Biology

  • Topics: Chapters 1-3

  • Key Concept: Cell Theory

    • Statement 1: All living things are made up of one or more cells.

    • Statement 2: Cells are the basic units of life

    • Statement 3: New cells arise from existing cells.

Cell Structure

  • Cell Components:

    • Nucleus: Control center of the cell containing DNA.

    • Cytoplasm: Jelly-like substance where cell components are suspended.

    • Mitochondria: the powerhouse of the cell, they generate ATP through cellular respiration.

    • Ribosomes: Synthesize proteins.

    • Chloroplasts: Organelles responsible for photosynthesis in plant cells.

    • Cell membrane: Controls the movement of substances in and out of the cell, maintaining homeostasis.

    • Cell Wall: A rigid outer layer that provides protection and structure to a plant cell

    • Vacuole: Store nutrients and water for the cell

DNA and Cancer

  • DNA:

    • Contains genetic information crucial for cell functions.

    • Four bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G).

  • Cancerous Cells:

    • Characterized by uncontrolled and rapid growth.

    • Caused by carcinogens and can be treated with radiation, chemotherapy, or surgery.

Mitosis and Cell Cycle

  • Mitosis Stages:

    • Prophase, Metaphase, Anaphase, Telophase

  • Cell Cycle Phases:

  • Mitosis: The division of the nucleus

    • Prophase: Chromosomes condense and the nuclear envelope breaks down.

    • Metaphase: Chromosomes align at the middle of the cell.

    • Anaphase: Chromosomes are pulled to opposite poles of the cell.

    • Telophase: Nuclear envelopes reform around the two sets of chromosomes.

  • Cytokinesis: The cytoplasm divides, resulting in two daughter cells.

    • Interphase: Longest phase where the cell grows and replicates its DNA in preparation for division.

Plant Organs

  • Three principal organs of seed plants:

    • Roots: Anchor the plant, absorb water and nutrients.

    • Stems: Support the plant and transport nutrients.

    • Leaves: Main site for photosynthesis and gas exchange.

    • Flower: Reproductive structure of the plant

  • Other structures: Xylem (water transport) and Phloem (nutrient transport).

Levels of Organization

  • From simplest to complex: Cells → Tissues → Organs → Organ Systems → Organisms

  • Connective tissue strengthen and support. It can be found near our bones, blood, fat, and ligaments

Organ Systems

  • Circulatory System:

    • Transports blood, oxygen, nutrients, and removes waste.

    • Composed of the heart, arteries, veins, and capillaries.

  • Digestive System:

    • Consists of organs that break down food and absorb nutrients.

    • Involves the mouth, stomach, intestines, liver, pancreas, and anus.

  • Interaction: The circulatory system transports oxygen provided by the respiratory system and nutrients absorbed by the digestive system.

Unit 2 - Chemistry

  • Key Concepts: Atoms, Compounds, and Chemical Reactions

  • Atoms Structure:

    • Composed of protons, neutrons, and electrons.

  • Bonding Types:

    • Ionic (transfer of electrons) and covalent (sharing of electrons).Law of Conservation of Mass:

      • In a chemical reaction, the total mass of the reactants equals the total mass of the products, meaning that matter cannot be created or destroyed.

  • Acid Characterization:

    Acids are substances that produce Hydrogen ions [H+] when dissolved in water, they are corrosive, and they typically have a sour taste and can turn blue litmus paper red. ALWAYS BONDED to NEGATIVE

  • Base Characterization:

    Bases are substances that produce Hydroxide ions [OH-] when dissolved in water, they feel slippery to the touch, have a bitter taste, and can turn red litmus paper blue. ALWAYS BONDED to POSITIVE

    a value on the pH scale differs from the value above or below it by a power of 10

  • Acid-Base Reactions:

    • Neutralization occurs when acids and bases react to form salt and water.

Unit 3 - Climate Change

  • Climate vs. Weather:

    • Weather: Short-term atmospheric conditions.

    • Climate: Long-term averages of weather patterns.

  • Factors Affecting Climate:

    • Sun's energy, atmospheric composition, hydrosphere, and plate tectonics.

  • Greenhouse Gases:

    • Water vapor, carbon dioxide, methane, and ozone.

Unit 4 - Optics

  • Light Properties and Behavior:

    • Reflection, refraction, and total internal reflection.

    • Index of refraction describes how light bends when entering different media.

  • Image Formation:

    • Plane mirrors produce virtual images that are inverted

  • Total Internal Reflection:

    • occurs when: angles of incidence are greater than the critical angle or when light travels from a medium in which it speed is lower to a medium in which its speed is higher

  • Apparent Depth:

    • an image created by a combination of the range of wavelengths visible to the human eye and the physical properties of light. Usually caused by light refraction

    • Objects placed in a denser medium appear to be at a lower depth

Miscellaneous Topics

  • Paleoclimatology: Study of past climates using ice cores, tree rings, and sedimentary rocks.

  • Emission Regulations: Understanding of carbon tax and cap-and-trade systems as methods for reducing greenhouse gas emissions.