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Bio 141 Lab Exam 1
Question | Answer |
---|---|
Why is there cytoplasmic connections in volvox? | Cellular communication between cells |
What solution is used when preparing slides of Trichtonympha | insect ringers (75% NaCl), isotonic to internal environment of insects |
What 3 variables were analyzed for influence on starch activity? | temperature, concentration, pH |
What is the relationship between Trichtonympha and termite? Which one has digestive enzyme to break down cellulose? | Mutualistic symbiosis; Trichtonympha |
Can you see organelles in a stereoscopic microscope? | No |
Key parts about a stereoscopic/dissecting microscope | low magnification, used for manipulating/viewing large objects; has a greater depth of field than cmpd microscope; light directed down at object is the "reflected/incident light"; light passing through object is "transmitted light" |
How was the reaction rate of amylase determined? | The rate of disappearance of amylose/starch |
What organelles are abundant in muscle cells? | mitochondria- provides ATP |
Compound Light Microscope identification | see pictures |
Stereoscopic Microscope Identification | see pictures |
What's the function of methylene blue? | Stains cells (in epithelial cell demo) |
What's the difference between a controlled variable and a control treatment? | Control variable: a variable kept constant between treatment groups Control treatment: level oft treatment that serves as a benchmark, usually not manipulated |
Which one(s) is/are eukaryotic? 1. elodea 2. protoccocus 3. cheek cells 4. volvox | all |
What are enzymes? What makes up enzyme substrate complex? | An enzyme is a biological catalyst that speed up a reaction without being consumed by the reaction. The substrate-enzyme complex is made up of an active site with the substrate bound in this site on the enzyme |
What criteria must exist in a hypothesis | must be testable, well defined, and falsifiable |
Dependent variable definition | One variable that is measure/counted or observed in response to the experimental conditions |
Independent variable definition | One variable or experimental condition to manipulate change |
Controlled variable definition | Variable that is kept constant during the course of the experiment |
Level of treatment definition | The value set for the independent variable |
Control | the independent variable is held at an established level or is omitted. It serves as a benchmark that allows the scientist to decide whether the predicted effect is really due to the independent variable |
Prediction | Designed to test a specific hypothesis; IF (a restatement of the hypothesis), THEN (predicting the results of the experiment) |
Table vs figures titles | Table: Not a statement; at the top Figure: A statement; below figure |
Line graphs vs Bar graphs | Line: continuous quantitative data; changes in quantity of a variable over their range Bar: represent separate or discontinuous groups or nonnumerical groups |
Hypothesis | Tentative explanation for an observation |
Compound Light Microscope function | designed to make objects visible that are too small to see w/o a microscope types: phase-contrast, darkfield, polarizing, Uv |
What is the condenser lens of a microscope? | used to focus light from the lamp through the specimen to be viewed |
What is the ocular of the microscope? | lens in the eyepiece (10x) |
The distance between the eyepieces | inter-pupillary distance |
Controls the amount of light passing through a specimen | Iris diaphragm |
What does catechol oxidase require to function? | copper, a coenzyme |
How can you detect whether or not an inhibitor is competitive? | If competitive, the reaction will reverse at increased concentration of substrate and produce a color change |
When preparing a test tube in enzyme labs, why wait until last moment to add substrate? | Because the reaction begins when the substrate and enzyme come into contact |
Identify an amoeba. How does it digest food? | Phagocytosis |
Which one is multicellular? 1) amoeba 2) Trichtonympha 3) Elodea 4) Protococcus | 3 |
What is the distance between occulars? | Interpupilary distance |
Why does the graph level off at higher concentrations? | The enzyme is saturated- all active sites are used |
Is compound microscope a light or electron microscope? | Light |
What happens to depth of field if we increase magnification? | depth of field decreases |
How do enzymes catalyze reactions? | They lower Ea to speed up reaction without being consumed |
Scientists are concerned about the effect of sulfur dioxide pollution on soybean production. 24 plants were treated to varying amounts of sulfur dioxide while the other 24 plants were exposed to filtered air. A) Indep. variable? B) Dep. variable C)control | A) plants exposed to sulfur dioxide B) soybean production C) plants exposed to outside air |
What is the difference between aggregate and a colony? | Aggregate: no evident interactions b/w cells Colony: collection of cells and found in repetitive numbers of organizations |
Which one has a cell wall? 1) Protococcus 2) Scenedesmus 3) Amoeba 4) Trichonympha | 1 and 2 |
What is the motion of "moving chloroplasts in cytoplasm" called? | cyclosis |
Look at stereoscope microscope. Identify 1) Incident light 2) transmitted light 3) focus knob | --- |
How do we test for presence of starch? If starch is present. what will we observe? | I2KI If starch present, we will see color change (gold/brown --> black/blue) |
Which one(s) have/has chloroplast? 1) Scendesmus 2) Volvox 3) Elodea 4) Protococcus | ALL |
What inhibits catechol oxidase? Is it competitive or non-competitive? | PTU- Phenylthiourea. Non-competitive |
What 2 enzymes were studied in the enzyme lab? | 1. Amylase 2. catechol oxidase |
What color does starch turn in I2KI? | black |
What are cofactors? Coenzymes? | Cofactors are nonprotein substances that the enzyme needs to bond in order for the enzyme to function Coenzymes are organic cofactors |
1. Is the image in the occular inverted relative to the specimen on the stage? 2. What os the distance between the specimen (letter) and the objective lens called? 3. Is distance greater with 10x or 40x? | 1. Yes 2. working distance 3. 10x |
Identify human cheek cell & nucleus | -- |
Identify trychonymoha. What is it's locomotive method? | flagella |
Which microscope can see ribosome and ER? | Electron microscope |
What is the depth of field? | The thickness of the specimen that may be seen in focus at one time |
What does elodea look like? With what microscope do you look at it through? | It is a leaf (plant). It has a cell wall, chloroplasts, etc. Stereoscope microscope |
Which type of microscope focuses a beam of electrons through a specimen and magnifies objects greatly? (100-1000x) | Transmission Electron Microscope (TEM) |
Which microscope is used for studying cells and tissues? | Scanning Electron Microscope (SEM) |
What are the parts of an amoeba? Is it multi or unicellular? | Cell membrane, ectoplasm (inside cell membrane), endoplasm, contractile vacuole, food vacuole, nucleus, pseudopodia |
What are the parts of trichonympha? Where do they live? What is the solution prepared for them? | Flagella (perhaps not for locomotion? unsure), Wood particles, nucleus. Live in gut of termites Solution: insect ringers- 75% saline that is isotonic (same concentration as internal environment of insects) |
Is protococcus aggregate or colonial? What can you see under the microscope? | Green algae, "Moss"; aggregate; you see 2-4 clusters of cell walled, cell membraned green bubbles |
Is Scenedesmus aggregate or colonial? What are the parts of Scenedesmus? | Colonial, groups of 4-8 Spines, cell wall, vacuole, chloroplast, nucleus (looks like a space alien/snowman) aquatic green algae |
Is volvox aggregate or colonial? uni or multicellular? Parts of a volvox? | Not colonial, multicellular Somatic cells, cytoplasmic connections, flagella, cell walls, nuclei, daughter colonies (product of sexual reproduction) |
Epithelial cells functions and parts (3) | Outside of animals, protect animals from water loss, mechanical injury, foreign invaders, and line interior cavities and ducts in animals Parts: nucleus, cytoplasm, cell membrane |
Define enzymes | biological catalysts that speed up a reaction by lowering the Ea of a reaction and do not get consumed or altered by a reaction |
Substrate | material which a catalyst reacts with in the active site, making the substrate-enzyme complex |
What is an activator? | Chemicals that must bind for the enzyme to be active |
What is a cofactor? | nonprotein substance that usually binds to the active site on the enzyme and are essential for the enzyme to work; could be a metal or a coenzyme |
What is an inhibitor? | chemical that shuts off the activity of specific enzymes. Can be competitive or noncompetitive |
What were the two enzymes tested in the enzyme experiment? | Catechol oxidase and amylase |
What is the formula of the reaction for catechol? | Catechol + O2 --> (catechol oxidase)--> Benzoquinone + H2O |
What is responsible for the browning of fruits? | Catechol melanin (Benzoquinone) |
What was the competitor? Was it competitive or non competitive? | PTU- phenylthiourea. It was noncompetitive |
What cofactor is needed for catechol oxidase? | Copper |