Untitled

Biology STAAR EOC Review

Reporting Categories and Questions Breakdown

  • Reporting Category 1: Cell Structure and Function
      - STAAR: 11 Questions
      - STAAR M: 9 Questions
      - Readiness Standards: 4
      - Supporting Standards: 5

Key Concepts

  • Biology: Study of life and living organisms.

  • Organism: Complete, individual, living thing.

  • Cells: Basic building blocks of life; smallest units of living things.
      - Prokaryotic Cells: Simple cells (e.g., bacteria).
      - Eukaryotic Cells: Complex cells (e.g., plant and animal cells).

Main Cell Parts or Organelles

  • Cell Membrane:
      - Function: Surrounds the cell; controls what enters and leaves; recognizes other cells; maintains homeostasis.

  • Cytoplasm:
      - Function: Suspends organelles; enclosed within the cell membrane.

  • Nucleus:
      - Function: Controls cell's activities; contains chromosomes made of DNA.

  • Mitochondria:
      - Function: Breaks down food to release energy.

  • Endoplasmic Reticulum (ER):
      - Function: Moves substances within the cell; exists as smooth or rough.

  • Ribosome:
      - Function: Makes proteins; round structures; located in rough ER.

  • Golgi Body or Complex:
      - Function: Changes and packages cell products.

  • Lysosome:
      - Function: Contains enzymes for digestion and chemical reactions.

  • Vacuole:
      - Function: Holds materials like water; larger in plant cells.

  • Plant Cell Specifics:
      - Cell Wall: Surrounds cell membrane; supports and protects plant cell.
      - Chloroplast: Contains chlorophyll for photosynthesis.

Cellular Processes

Homeostasis

  • Definition: The process by which organisms maintain stable internal conditions despite changes in the external environment.
      - Importance: Essential cellular processes require specific internal conditions.
      - Equilibrium: Another name for homeostasis.
      - Maintenance: Controlled by plasma membrane regulating entry/exit of materials.

Cell Membrane Functions

  • Protective Barrier

  • Regulate Transport: Selectively permeable; allows small and hydrophobic molecules (e.g., O₂, CO₂, H₂O) to pass through easily while ions and large hydrophilic molecules cannot.

  • Cell Recognition

  • Anchoring Sites for Cytoskeleton

  • Binding Sites for Enzymes

  • Cell Junctions

  • Contains Cytoplasm

Types of Transport Across Cell Membranes

  1. Simple Diffusion: No energy required; molecules move from high to low concentration area.
       - Example: Liquid diffusion through a membrane.

  2. Osmosis: Diffusion of water; moves towards high solute concentration.
       - Types of Solutions:
         - Isotonic: No net water movement.
         - Hypotonic: Causes cell swelling (cytolysis).
         - Hypertonic: Causes cell shrinking (plasmolysis).

  3. Passive Transport: High to low concentration; no energy required.
       - Facilitated Diffusion: Uses transport proteins; moves substances across the membrane.

  4. Active Transport: Requires energy (ATP); moves substances against the concentration gradient (low to high).
       - Example: Na⁺-K⁺ pump.

Protein Types in Transport

  • Channel Proteins: Embedded in the cell membrane; provide pores for materials.

  • Carrier Proteins: Change shape to move materials across.

Bulk Transport Mechanisms

  • Exocytosis: Molecules move out of the cell via vesicles fusing with the membrane.

  • Endocytosis: Large molecules enter the cell by vesicle formation.
      - Types:
        - Pinocytosis: Takes in dissolved molecules.
        - Phagocytosis: Engulfs large particles.
        - Receptor-Mediated Endocytosis: Specific to certain hormones or nutrients.

Summary of Cellular Processes

  • Homeostasis: Regulation of internal balance.

  • Energy Conversions: Photosynthesis and respiration processes.

  • Molecule Transportation: Various means of translocation across cell membranes.

  • Synthesis of New Molecules: Production of complex molecules from simpler ones.

Structures of Viruses and Cells

Virus Characteristics

  • Definition: Nonliving particles; made of proteins, nucleic acids, and sometimes lipids.

  • Structure:
      - Core of DNA/RNA, protein coat (capsid), sometimes an envelope.

Viral Reproduction

  1. Attachment: Virus binds to a host cell.

  2. Genetic Material Injection: Viral DNA/RNA enters.

  3. Lytic Cycle: Host cell produces new viruses and eventually is destroyed.

  4. Lysogenic Cycle: Viral DNA is incorporated into host DNA; can remain dormant.

Examples of Disease-causing Viruses

  • HIV: Causes AIDS; attacks helper T cells.

  • Influenza: Infects respiratory tract; can mutate rapidly.

Cell Cycle and Mitosis

Phases of the Cell Cycle

  1. G1 Phase: First growth phase.

  2. S Phase: DNA replication; synthesis of DNA.

  3. G2 Phase: Preparation for mitosis; protein production.

  4. M Phase (Mitosis): Division of nucleus and cytoplasm (cytokinesis).

Importance of the Cell Cycle

  • Critical for growth and repair of organisms.

Mitosis Stages

  1. Prophase: DNA coils to form visible chromosomes; spindle fibers form.

  2. Metaphase: Chromosomes align at the cell's equator.

  3. Anaphase: Chromatids are pulled apart.

  4. Telophase: Cells start to split; nucleus re-forms.

Genetic Material and Molecular Biology

DNA and RNA

  • DNA: Composed of nucleotides (phosphate, deoxyribose sugar, nitrogenous base); carries genetic information.

  • Gene Expression: Involves transcription (DNA to mRNA) and translation (mRNA to protein).

  • Mutations: Changes in DNA structure which can lead to diseases, including cancer.

Rates of Reproduction and Evolution

Mechanisms of Genetics

  • Mendelian Genetics: Involves traits inheritance through alleles.

  • Natural Selection: Process where organisms better adapted to their environment tend to survive and produce more offspring.

Summary of Environmental Biology

Ecological Interdependence

  • Symbiosis: Various interaction types among species—mutualism, commensalism, parasitism.

  • Succession: Gradual replacement of species in an area; primary & secondary succession defined.

Responses and Adaptations

  • Organisms exhibit different adaptations to their environments; examples include genetic variation ensuring species survival.

Impact of Changes

  • Environmental changes can disrupt ecosystems leading to declines and extinctions.