Lab Practical 1 Study Guide PDF

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an outline of every question on the 1st lab practical including the answer...

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BIOLOGY 101 PRACTICAL #1 REVIEW SHEET Lab 1 - Measurement  Know how to convert between the units of length, mass, and volume o To covert from unit to another:

¿ of units you have ×

units you want =¿units you want units you have

Units of Length Prefix Kilo Meter Deci Centi Milli Micro

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Symbol k m dm cm mm um

Nano

nm

Units of Mass Kilo Gram Milli Micro

Symbol kg g mg um

Value 1 km = 1000 m 1m 1 m = 10 dm 1 m = 100 cm 1 m = 1,000 mm 1 m = 1,000,000 um 1 mm = 1,000 um 1 m = 1,000,000,000 nm 1 um = 1,00 nm Value 1 kg = 1,000 g 1g 1 g = 1,000 mg 1 mg = 1,000 ug

Units of Volume Symbol Value Liter L 1L Deci dl 1 L = 10 dl Milli ml 1 L = 1,000 ml Micro ul 1 ml = 1,000 ul o Length: the measurement of a line from one point to another o Volume: the amount of space an object occupies o Mass: the quantity of matter in a given object o Temperature: the degree of how hot/cold an object is Know the standard unit for each type of measurement o Length: meter o Volume: liter o Mass: gram o Temperature: Celsius Be familiar with the glassware and apparatus used in lab o Length: metric ruler or meter stick o Volume: beaker, graduated cylinder, Erlenmeyer flask o Mass: electronic balance or scale o Temperature thermometer Know how to accurately measure an object using the appropriate apparatus and standard unit o To read the volume of an object in a graduated cylinder, read from the bottom of the meniscus at eye level  The meniscus is the curve of the liquid in the container Know how to convert between the Celsius and Fahrenheit temperature scales o o

5 ℃= ( ℉−32 ) 9 9 ℃+32 ℉=¿ 5

Lab 2 - Scientific Method  Know the definitions of independent, dependent and control variables o Independent variable: treatment or condition that is manipulated by experimenter  Follows “if” of prediction o Dependent variable: event that is measured or observed

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 Follows “then” of prediction o Control variable: all factors that are kept constant Know the definition of a control group and an experimental group o Control group: not treated with the independent variable o Experimental group: treated with the independent variable Be able to identify the variables and groups present within a given scenario o Independent variable: the amount of water given to the dandelions o Dependent variable: the growth of the dandelions o Control variable: soil, light, temperature o Control group: container 3, which receives the normal, daily requirement of water o Experimental group: containers 1 and 2 which receives less than the normal amount of water Know the order of the scientific method as well as what each step entails o Step 1: observation  Qualitative data: use of senses (from nature or journal article)  Example: plants need water in order to grow o Step 2: question  Observation turned into a question  Example: what will happen to the plant if given less water than required? o Step 3: hypothesis  Tentative answer to the question, based on reasoning  Example: plants which receive less water will not survive o Step 4: prediction  Assume the hypothesis is correct and make a prediction about the outcome of a test  Usually in the form “if…., then” statement  Example: of plants do not receive enough water, then they will die o Step 5: experiment  Tests the prediction  Must be repeatable  Increase sample size  Multiple trials  Accurate description of materials used, including quantities  Goal: to be accepted by scientific community (published in academic journal)  Example: dandelions will be gown in three separate containers and growth over time will be measured  Container 1: no water  Container 2: watered once every two days  Container 3: watered daily o Step 6: conclusion  Use results to evaluate hypothesis  Accept or reject hypothesis  May lead to further questions and experimentation  Example: upon completing the experiment, the results indicate that both container 1 and container 2 experienced decreased growth when compared to container 3. The hypothesis that less water would inhibit the growth of dandelions is accepted 

Lab 3 - Information Literacy  Know what type of information each resource (reference, primary, secondary and popular press) provides as well as examples of each o Reference:  Includes:  Almanacs  Bibliographies  Dictionaries  Directories  Encyclopedia  Provides:  Biographies  Chronologies  Definitions  Facts

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Benefits:  Provide overview of topic, important facts, and background information  Written in language that is easily understood  Good starting point of scientific research and research papers Limitations:  Lacks detail

Primary:  Includes:  Original research articles  Provides:  Original research findings written by scientists that conducted the experiments  Quality control (journal articles are reviewed by other scientists in the field prior to publication; “peer-review”)  Benefits:  Provide detailed description of individual experiments  Provide references to other experiments and scientists in the field  Source for latest findings in specific areas  Limitations:  Narrow in focus  Difficult to read; requires level of expertise in specific area o Secondary:  Includes:  Annual Reviews  Books and Textbooks  Articles in Scientific Journals- Review Articles  Provides:  Detailed historical perspective and biographical information  Facts  Summaries of scientific work  Benefits:  Detailed overview of topic  Synthesis and summary of past secondary works  Written in language to engage broad audience; not just scientists involved in the field  Limitations:  Not as current as information found in primary literature  Lack detailed description of individual experiments o Popular Press:  Includes:  Magazine Articles  Newspaper Articles  Articles found on the World Wide Web  Provides:  Layman’s summary of scientific findings  Benefits:  Distributed to wide audience  Limitations:  Validity: all popular press articles must be carefully evaluated  Not always written by experts in the field Know which type of reference has more validity in a scientific community o ?? o

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Lab 4 - Microscopy  Know the parts of the compound light microscope o Adjustment knobs  Coarse adjustment knob: locates specimen and brings it into approximate focus  Fine adjustment knob: brings the specimen into final focus o Arm: supports upper parts of microscope and serves as a carrying handle o Base: bottom part of microscope and supports the stage and arm o Body: connects the nosepiece and eyepiece o Diaphragm: regulates the amount of light used to view the object o Eyepiece (ocular): series of lenses (top) through which an object is viewed

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Light source: lamp that directs a beam of light through the specimen Nosepiece: revolving piece that holds objectives and has lenses used to magnify the specimen Objectives  Scanning-power objective:  Holds 4x lens  Shows the whole slide  Low-power objective:  Holds 10x lens  Shows the object in greater detail  High-dry objective:  Holds 40x lens  Shows the object in even greater detail Stage: holds and supports microscope slides Slide position adjustment knob: moves slide left to right and front to back Stage clips: level that opens to secure the slide on the stage

Eyepiece (ocular)

Body

Nosepiece Objectives Arm Stag Diaphragm Course adjustment knob Slide position adjustment knobs Fine adjustment knob Light source

Base

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Know the magnifications of all individual lenses (ocular and objectives) Objective Lens Objective Lens Ocular Magnification Total Magnification Magnification Scanning (red) 4 10 40x Low (yellow) 10 10 100x High dry (blue) 40 10 400x  Know how to calculate total magnification o Multiply the magnification of the objective lens by the ocular magnification  Know the three basic concepts of microscopy o Magnification: the amount an image is enlarged  How much larger a specimen appears compared to its actual size o Resolution: the extent to which image detail is preserved  Resolving power: the extent to which two structures can be distinguished from one another o Contrast: the ability of an image to stand out against its background o Other terms:  Working Distance  Distance between objective and slide on stage  As you increase the magnification, you decrease the working distance  Field of View/ Diameter of Field  As you increase the magnification, you decrease the field of view  Contained in a circle  In micrometers  Parfocal  When you change the lenses (to a higher or lower power) the image will always remain in focus  Parcentral  When you switch objective lenses, the image will stay in the center of your field of view  Depth of focus  The vertical distance that remains in focus at any one time  Be familiar with the uses of the various types of microscopes o Light Microscopes  Form images using lenses and wavelengths of light in the visible spectrum  Color image  Living or nonliving specimen  40x-1000x magnification  Examples:  Compound Light Microscope: o Thin sections of specimen  Light has to be able to pass through to see inside the organism o Used to study thin sections of specimens or living microorganisms o An internal light source illuminates the specimens from below o Uses two lenses at a time (“compound”)  Stereo Dissecting Microscope o Light shines down on specimen to view outer surface detail o Electron Microscope  Use beams of electrons to form images  Black and white images  Only nonliving specimen  350,000x magnification  Specimens coated in metal (usually gold)  Examples:  Transmission Electron Microscope (TEM): o Thin sections of specimen o Used to study internal structures of cells o An extremely thin section of specimen is stained with heavy metal and placed in a column in the scope. A beam of electrons is passed through the specimen and electromagnets are used to form the image  Scanning Electron Microscope (SEM): o 3D surface details

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Used to study the surface of specimens in three dimensions An electron beam scans the surface of the specimen, which has been coated in gold. The beam excites electrons in the gold, and the excited electrons are focused to form an image

Lab 5 - Chemical Composition  Know the monomers and polymers of each organic molecule o Carbohydrates  Monomer: monosaccharide (glucose)  Polymer: polysaccharide (starch) o Lipids  Monomer: glycerol and fatty acids  Polymer: no name  Example: triglycerides o Proteins  Monomer: amino acids  Polymer: polypeptide o Nucleic Acids  Monomer: nucleotide  Polymer: polynucleotide  Know the reagents used to test for sugar, starch, lipid, and protein o Benedict’s Test  Detects monosaccharides and disaccharides  Glucose o Lugol’s Iodine  Detects polysaccharides  Starch o Sudan IV  Detects lipids o Biuret’s Test  Detects protein  Albumin  Be able to distinguish between positive and negative results for each test o Benedict’s Test  Negative: blue  Positive: red o Lugol’s Iodine  Negative: orange/brown  Positive: blue/black color o Sudan IV  Negative: pink  Positive: red o Biuret’s Test  Negative: blue  Positive: purple Lab 6 - Cell Structure & Function  Be able to identify prokaryotic and eukaryotic cells under a microscope o Eukaryotic cells will have a nucleus visible in the center of specimen under the microscope o Slides with prokaryotic cells will have many specimens on it o Slides with eukaryotic cells will have fewer specimens on it  Know the parts of the animal and plant cell models

Animal Cell

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Know the functions of all cellular organelles o Cell wall (plant)  Maintains shape and structure  Prevents busting o Plasma membrane  Controls what enters/exists the cell  Selectively permeable phospholipid bilayer o Nucleus  Contains DNA  Maintains genes and controls activities of the cell o Nucleolus  Sub-organelle of the nucleus  Produces ribosomes o Ribosome  Produce proteins o Rough endoplasmic reticulum  Contains ribosomes  Processes and packages proteins o Smooth endoplasmic reticulum  No ribosomes  Produces and processes lipids o Golgi apparatus  Sorts and ships organic molecules o Mitochondrion  Convert organic materials to energy (ATP) o Lysosome (animal)  Contains digestive enzymes o Fat vacuole (animal)  Storage of fat o Chloroplast (plant)  Site of photosynthesis o Central vacuole (plant)  Storage of water (50-70%) of cell o Centriole (animal)  Aids in cell division o Cytoplasm  Liquid component containing the organelles Be able to identify bacteria by their shape

Plant Cell

Coccus (plural: cocci)  Round o Bacillus (plural: bacilli)  Rod o Spirillum (plural: spirilla)  spiral Be able to recognize Gram-positive and Gram-negative bacteria o Gram stain is used on prokaryotes (bacteria) o There are two groups: gram negative or gram positive o Positive: purple o Negative: red o

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Lab 7 - Diffusion & Osmosis  Know the definitions of solvent, solute, solution, diffusion, and osmosis o Solvent: liquid the solute dissolves in  Example: water o Solute: substance dissolving  Example: sugar or salt o Solution: solute dissolved in solvent o Diffusion: net movement of molecules or atoms from a region of high concentration to a region of low concentration o Osmosis: simple diffusion of water  There is a semi-permeable membrane  Water will move to the solution with the highest solute concentration (water is greedy)  Be familiar with tonicity: hypertonic, hypotonic, and isotonic solutions o Tonicity: the ability of a solution to cause a cell to gain or lose water o Hypertonic: higher solute concentration o Hypotonic: lower solute concentration o Isotonic: equal solute concentration  Know how water movement across membranes is affected by the above tonic solutions o Hypertonic solutions:  There is excess amount of solute outside of the cell o Hypotonic solutions:  There is less solute on the outside of the cell; more solute in the cell o Isotonic solutions:  Equal amount of solute outside and inside of the cell  Know the terms crenation, lysis, turgid, and plasmolysis and how they relate to animal and plant cells o Crenation: water loss through osmosis (cell shrivels)  This is in animal cells o Lysis: cell ruptures due to excess water  Cells will explode and die o Turgid: full of water  Plants like to be turgid o Plasmolysis: loss of water (inside of the cell shrinks)  This is bad; not enough water for plant cell  Understand how cell size affects the efficiency of diffusion o When the cell increases in size, the volume increases faster than the surface area because volume is cubed where surface area is squared o When there is more volume and less surface area, diffusion takes longer and is less effective o By reducing cell size, cells are greatly increasing the surface area to volume ratio which makes diffusion/osmosis much more effective o Cellular concentration of ions, nutrients, salts, etc. can occur much more quickly and efficiently o The ability to use the gradient for the next “job” is important o If the volume of a cell was large, the ability to quickly change the concentration would decrease  Be able to distinguish an acid or base using phenolphthalein o Phenolphthalein is an acid/base indicator o Basic: pink o Acidic: clear  Know the factors that affect the rate of diffusion o Temperature

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Increase temperature = increase rate of diffusion

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Size

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 Smaller molecules diffuse faster Concentration  Greater difference in concentration = increase rate of diffusion...