Bio Study Guide PDF

# Bio study guide ## Parts of a microscope - Tube - holds eyepiece & lens at proper distance - Revolving nose piece - rotating disk, holds 3 lenses, changes magnifications - Objective lenses - magnify 4x, 10x, 40x - Stage clips - holds slides in place - Diaphragm - controls amount of light reachin...

# Bio study guide ## Parts of a microscope - Tube - holds eyepiece & lens at proper distance - Revolving nose piece - rotating disk, holds 3 lenses, changes magnifications - Objective lenses - magnify 4x, 10x, 40x - Stage clips - holds slides in place - Diaphragm - controls amount of light reaching object - Light source - shines light through object - Ocular lens - part you look through, lens magnifies 10x - Arm - connects base to tube, used for carrying - Stage - supports object - Coarse adjustment - moves stage up or down (focus) Avoid on high power - Fine adjustment - focuses object under medium or high power ## Cell theory - **Three points of cell theory:** - Cells are the smallest functional unit of life. - All organisms are composed of one or more cells. - All cells are produced from other cells. - **Aristotle** created abiogenesis & spontaneous generation - Abiogenesis - idea that life could emerge from non-living matter. - **Redi** believed abiogenesis was not true. - **experiment** - two meat in jars, one sealed one not. Open had life, closed did not. - **Pasteur** also believed abiogenesis was not true. - **experiment** - glass flask with S shaped neck. - Filled the flask with broth, then boiled broth - S shaped necks allowed air to enter, any microorganisms would be stuck. - Both were clear after days - Created **Biogenesis** - idea that life could only emerge from living matter. - **Hooke** - used CLM microscope, observed cork cells and noticed "tiny rooms." He named them cells. - **Leeuwenhoek** - first scientist to observe single-celled organisms (bacteria). He named them animalcules. - **Schleiden** - observed all plants were made of cells - Proposed nucleus (center of cell) was responsible for development. - **Schwann** - studied animal cells and observed the same characteristics. - **Schleiden/Schwann** reasoned where there's nuclei, there's cells. - Also determined cells are the basic unit of life. - **Virchow** - observed bone cells develop from cartilage cells. - Discovered cells divide to produce more cells, cells arise from pre-existing cells. ## Parts of a cell - The basic unit of life and must perform: - Obtain food/energy - Reproduction - Convert energy - Carry out chemical reactions - Eliminate wastes - Growth - **Basic types of organisms:** - **Eukaryotes** - multicellular, composed of nucleus & organelles (plants/animals) - **Prokaryotes** - single-celled, lack nucleus & organelles (bacteria/algae). - **Organelles** - open systems that exchange energy/matter. Internal cell structures that carry out specific functions for the cell. - **Nucleus** - controls all cellular activities. Materials leave through the nuclear pores in the nuclear envelope that surrounds the nucleus. - **Nucleolus** - region in the nucleus where ribosomes are made. - **Cell membrane** - protective barrier for the cell, transports nutrients/materials into the cell, wastes out of the cell. - **Rough ER** - attached to the nucleus, has ribosomes, produces proteins - **Smooth ER** - attached to Rough ER, no ribosomes, produce lipids. - **Golgi apparatus** - packages/sorts proteins from Rough ER, flat disc shaped stacks. - **Vesicles** - transport substances through the cell. - **Lysosomes** - specific vesicle, contains digestive enzymes which destroy dead or bad parts of the cell, or invading bacteria. - **Mitochondria** - produces energy through cellular respiration. Sugars converted into usable energy or ATP. - *C₆H₁₂O₆ + 6O₂ → 6H₂O + 6CO₂ + ATP* - **Vacuoles** - balloon like vesicles, store water, food, minerals, or wastes - Animal cells: have many small. Plant cells: have one large - **Cytoplasm** - gel substance enclosed within cell membrane, suspends organelles in place. - **Centrioles** - help separate DNA during cell division (animal cells only). - **Cell Wall** - protects plant cells, provides shape/support (plant cells only). - **Chloroplasts** - organelle produces energy by Photosynthesis. Flattened disks of Chlorophyll that give plants their color. - *6CO₂ + 6H₂O + energy (light) → C₆H₁₂O₆ + 6O₂* ## Properties of the cell membrane: - **Phospholipid bilayer** - consists of two layers. - **Hydrophilic** (water loving) head - **Hydrophobic** (water hating) tail - **Integral proteins** - extend through the entire membrane. - **Channel proteins** - always open, allows ions & water to freely flow through. - **Carrier proteins** - open/close from energy (ATP), transport large molecules (sugars/fats). - **Peripheral proteins** - attach to membrane, temporarily provide general support. ## Cell Size & Function - **Why cells are so small:** - Diffusion over long distances is slow; minimize distance for access to oxygen, substances, nutrients, etc., faster. - **Plant structure & specialization:** - **Cell specialization in Plants** - 4 organs in plants: roots, stem, leaf, flower - **Photosynthesis** - occurs in chloroplasts of plant cells. - *6CO₂ + 6H₂O + light (energy) → C₆H₁₂O₆ + 6O₂* - **Cellular respiration** - occurs in mitochondria of cells. - *C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)* ## Parts of a leaf cell: - **Epidermal Tissue** - flat single layer of cells on the upper/lower leaf. - Protects leaf, has no chloroplasts, *cuticle*: clear layer prevents evaporation through the leaf. - **Palisade tissue** - long narrow columns of cells under the epidermis (main area of photosynthesis, has chloroplasts) - **Spongy tissue** - round loosely packed cells under the palisade tissue (main area of water/gas exchange, minor photosynthesis, some chloroplasts). - **Stomata** - tiny openings on the bottom of the leaf, allows exchange of CO₂, O₂, H₂O. - **Guard cells** - cover stoma to allow substances in/out. - **Vascular tissue** - tubes arranged in vascular bundles. - **Xylem** - carries water/minerals from the roots to the leaves. - **Phloem** - carries sugars from leaves to the rest of the plant. ## Vesicle-mediated transport - **Used to facilitate movement of substances** - **Endocytosis** - membrane forms pocket around substances the cell wants to take in, transports the particle to specific parts of the cell. - **Phagocytosis** - takes large solid particles. - **Pinocytosis** - takes small fluid droplets. - **Receptor-mediated endocytosis** - receptors bind to compounds and take them in. - **Exocytosis** - reverse of endocytosis, vesicles fuse with the membrane and release particles out of the cell. ## Tonicity - **Tonicity** - ability of a solution to move water in/out of a cell through osmosis. - **Comparison** of amount of water inside to outside the cell. - **Solute:** substance that dissolves. - **Solvent:** substance that does dissolving. - **Solution:** solute & solvent together. ## Osmosis - **Hypotonic** - solute inside the cell is greater than outside, which causes water to move into the cell (cell swells up/bursts) - **Hypertonic** - solute outside the cell is greater than inside, which causes water to leave the cell (cell shrinks/shrivels). - **Isotonic** - solute inside and outside is equal, which causes water to move in/out equally. - **Tonicity of the cell is always opposite to the tonicity of the solution**. - Hypotonic cell = hypertonic solution. ## Water & Sugar transport: - **Adhesion:** attraction of water molecules to other substances. - **Cohesion:** attraction of water molecules to other water molecules. - **Capillary action:** ability of water to cling to the surface of a solid. - **Move fluids by adhesion/cohesion** - **Root hairs** - increase surface area for gas exchange. - **Root cells** - take up water by osmosis, minerals through active transport - **Xylem sap** - 581-6000 of water and dissolved minerals. - **Xylem vessels** - dead, hollowed-out cells, carry xylem sap up to stems/leaves. - **Root pressure:** pushes as water moves in root cells from osmosis. - Pressure builds up, water moves from high to low pressure in the roots. - **Transpiration pull** - evaporation of water through stomata/lenticels pulls water up the stem into leaves. - Root pressure/transpiration use cohesion/adhesion. - **Sugar moves downwards through phloem** - sugars are translocated to stems & roots by phloem vessels. - **Phloem vessels** - living cells (sieve tubes), connected by sieve plates. - **Companion cell** - helps sieve tube offering support. - **Sugar/minerals enter phloem from active transport** (called phloem sap). ## Gas exchange in plants - In leaves, CO₂, O₂, and H₂O move by diffusion from plant cells/air. - Gases enter/exit leaves from stomata. - **Day:** CO₂ consumed, O₂ released (photosynthesis). - **Night:** O₂ consumed, CO₂ released (cellular respiration). - **Water is lost by evaporation (transpiration) to maintain turgor pressure.** - **Open/closing of stomata** is by turgor pressure in guard cells. - Stomata open for water, close when loses too much water. - **Turgor pressure** - how much water in the cell. - A lot of water = high turgor pressure, guard cells open/swell - Not much water = low turgor pressure, guard cells close/shrink. - **Lenticels** - lens-shaped openings allow gas exchange (woody plants). ## Plant control systems: - **Stimuli** - changes in the environment trigger responses in organisms. - **Tropism** - responses to stimuli. Plant grows away/toward stimulus. - **Phototropism** - allows the stem to curve away/toward light. - **Positive:** grow towards light. - **Negative:** grow away from light. - **Gravitropism** - growth due to gravity. - **Positive:** growth into the soil, towards force of gravity. - **Negative:** growth upwards, against force of gravity. - **Nastic response** - plants respond to touch.