Living Things Characteristics Quiz (MRS GREND)

Living Things - Characteristics (MRS GREND)

• Movement: Ability of an organism to relocate (bend, sway, etc.)
• Respiration: Cellular respiration breaks down nutrients (like sugar) using oxygen to produce energy (ATP); carbon dioxide is a byproduct. (Glucose + Oxygen → Energy + Carbon dioxide + Water)
• Sensitivity: Ability to detect and respond to environmental changes.
• Growth: Increase in size of an organism.
• Reproduction: Passing genetic information to offspring.
  • Asexual: Offspring are identical to the parent (e.g., some trees).
  • Sexual: Offspring inherit genetic material from two parents.
• Excretion: Removal of cellular waste (e.g., toxins in urine, sweat).
• Nutrition: Acquiring and processing nutrients for energy, growth & development.
  • Heterotrophs: Consume other organisms for nutrients (e.g., glucose).
  • Autotrophs: Produce their own food using sunlight (photosynthesis). (Light Energy + Carbon Dioxide + Water → Glucose + Oxygen)
• Death: Limited lifespan for all organisms.

Hierarchical Organization of Living Things

• Organism: A single living individual (e.g., a person).
• Organ System: Group of organs working together for a function (e.g., digestive system).
• Organs: Structures of tissues performing a complex function (e.g., stomach).
• Tissues: Collection of similar cells with a common function.
  • 4 Main Animal Tissues:
    • Epithelial: Skin and linings.
    • Connective: Support (bone, tendons).
    • Muscle: Movement.
    • Nervous: Communication.
• Cells: Basic unit of life.
• Organelles: Tiny organs within a cell (e.g., nucleus).

Cell Theory

• All organisms are composed of one or more cells.
• The cell is the basic unit of life.
• All cells come from pre-existing cells.
• Cell function determines organism health.

Organelle Structure and Function

• Nucleus: Round/oval, central, dark-colored; controls cell activity, contains DNA, makes ribosomes.
• Centrioles: Small cylinder shapes; create spindle fibers for cell division (animal cells only).
• Cytoplasm: Jelly-like substance filling the cell, cushions organelles, contains necessary chemicals.
• Cell Membrane: Double-layered fat surrounding all cells, controls movement of materials in/out.
• Mitochondria: Sausage shape; makes energy (ATP) through cellular respiration.
• Golgi Apparatus: Pancake stack; packages proteins for transport within/out of the cell.
• Endoplasmic Reticulum (Rough & Smooth):
  • Rough ER: Has ribosomes; makes proteins for the cell's use.
  • Smooth ER: No ribosomes; makes fats, cleans the cell.
• Ribosomes: Small round dots; make proteins.
• Lysosomes: Round sacs containing enzymes to break down waste.
• Vacuoles: Large sacs; store water, food, & waste.
• Cell Wall: Thick, tough layer surrounding the cell membrane in plant cells, provides protection and support.
• Chloroplasts: Green discs site of photosynthesis (plant cells only).

Animal vs. Plant Cells

• Plant cells have a cell wall and chloroplasts, animal cells do not.

Prokaryotes vs. Eukaryotes

• Prokaryotes: Unicellular, lack membrane-bound organelles; examples include bacteria, archaea.
• Eukaryotes: Unicellular or multicellular, have membrane-bound organelles; examples include plants, animals, fungi, protists.

Microscopy

• Magnification Calculation: Objective lens magnification × eyepiece magnification.
• Microscopes & Specimens: Images are larger, flipped, and sometimes artificially colored; 2D view of a 3D specimen.

Cell Division

• Reasons for Cell Division: Reproduction, growth, repair.

Diffusion & Osmosis

• Diffusion: Movement of molecules from high to low concentration (dynamic equilibrium).
• Osmosis: Movement of water across a semi-permeable membrane from high to low concentration.
• Examples of substances that move by diffusion: oxygen, carbon dioxide.

Surface Area to Volume Ratio (S:V)

• S:V ratio decreases as cells grow; smaller cells have higher ratio.
• Important for nutrient exchange & waste removal in cells.

Cell Cycle

• Series of phases (G1, S, G2, M) leading to cell division.

Cell Cycle Checkpoints

• G1 Checkpoint: Assesses cell size, nutrients, DNA integrity, & growth signals.
• G2 Checkpoint: Checks for DNA damage and repairs.
• Spindle Checkpoint: Ensures correct attachment of chromosomes to spindle fibers during mitosis.

Mutations

• Mutations: Permanent changes in DNA; can be caused by genetic factors, radiation, chemicals, or viruses.

Cancer Cells

• Cancer Characteristics: Uncontrolled cell division, rapid division, damage to surrounding cells, metastasis (spread).

Cancer Diagnosis

• Various methods like endoscopy, X-rays, ultrasounds, CT scans, MRI, biopsies, and genetic screening.

Cancer Treatment

• Methods: Surgery, chemotherapy, radiation therapy, biophotonics, and immunotherapies.

Stem Cells

• Embryonic Stem Cells: Unlimited potential to differentiate into various cell types.
• Adult/Tissue Stem Cells: Limited potential, mainly capable of replenishing specific tissues.

Specialized Cells (Structures & Functions)

• Red Blood Cell: Small, lacks nucleus; transports oxygen.
  • Shape increases surface area for oxygen exchange.
  • Lack of nucleus maximizes space for hemoglobin.
• Nerve Cell: Long, thin extensions; transmits electrical signals.
  • Complex structure allows for rapid signal transmission.
• Muscle Cell: Long, cylindrical; contracts to cause movement.
  • Specialized proteins allow for contraction.