Biol 5 (Laboratory) Flashcards
The ___ is a systematic approach in pursuit of truth based on rationality and logic
Scientific method
An ____ is information taken from the real world and made by humans directly (using their five senses) or by using instruments
Observation
A ___ is useful if it explains a problem, suggest new idead and make predictions that can be tested.
Hypothesis
Two kinds of hypothesis
Descriptive and explanatory
An overall statement which provides a basis for predicting things not yet observed
Descriptive
A tentative explanation of, or even a guess at what caused the pattern under observation
Explanatory hypothesis
____ hypothesis may be formulated to design better experiments and explore more possibilities in testing the main hypothesis
Alternative hypothesis
All observation and information called ___ are properly recorded and analyzed
Data
___ are made up of various chemical components. The chemical compounds present can be divided into two principal classes: ___ and ___
Cells
Inorganic
Organic
____ are molecules, usually small that typically lack carbon and in which Ionic bond play an important role
Inorganic compounds
___ include water, oxygen, carbon dioxide and many salts, acids and bases
Organic compounds
•___compounds always contain carbon and hydrogen.
Large organic molecules includes ___, ___, ___, ___
Organic compounds
Lipids, carbohydrates, protein and nucleic acids
To test the presence of starch add 2 drops of ____
Iodine solution
Benedict test for the presence of sugars add ___
Benedict solution
To test Biuret test for the presence of proteins add ____
Sodium hydroxide and copper sulfate
To test for the presence of lipid add ___
Sudan III or IV
the equipment was based on the prototype invented by ___ whose first specimen was ___
Anton Van Leeuwenhoek
Pond water
Compound microscope is composed of three major parts ;
Optical
Illuminating
Mechanical
Compound light microscope considers three parameters;
Magnification
Resolution
Contrast
___ Power is the ability to distinguish two adjacent objects as distinct and separate
Resolution
The___ is the diameter of the viewing field measured at an intermediate plane of angle
Microscopy field of view
• The control knobs, used to focus the microscope on the specimen
•__ a smaller knob, used to sharpen the image
•__ used for focusing under low power magnification
Adjustment knobs
Fine adjustment knobs
Corse adjustment knobs
Used to move the stage mechanically there are two knobs; one for moving left and right and other for moving forward and backward
Stage control knobs
A hole in the microscope stage through which the transmitted light from the source reaches the stage
Aperture
Known as the iris found under the stage of microscope control rhe the amount of light that reaches the specimen
Diaphragm
Used to collect and focus light from the illuminator into the specimen. Found under stage next to the diaphragm of the microscope
Condenser
A light source can be a mirror which reflects the light from an external source to the sample or electric bulbs of low voltage are used as a constant light source
Microscopic illuminator
Magnification extends are ability to observe details 1000 times, so that we can see objects as small as ___in diameter
0.1 micrometer
Set of related hypothesis supported by many observation and experiment
Theory
Theory had been tested repeatedly and not proven false
Law
An ___ is a controlled method of testing a hypothesis
Experiment
___ are designed to provide an opportunity to make observation that will help us test a hypothesis
Experiment
Experiments are best understood in term of three types of variables
- Independent variable
- Dependent variable
- Controlled variable
Most experiment are repeated multiple times with slight variations these repetition are often called __
Trials
A variable that is purposely altered between trials is called an ___
Independent variable
Usually, it Is best practice to have a ___ in an experiment
Single independent variable
It may be helpful to think of the independent variable as the ___ of the experiment
Input
If the independent variable is the input of an experiment then the dependent variable is the___
Output
____ change in response to the independent variable, it is the variable being measured
Dependent variable
____ are kept constant so that their fluctuations do not alter the dependent variable and cloud its relationship with the independent variable
Controlled variable
A ____ happens when molecules move from one physical state of matter (solid, liquid, or gas) to another physical state. There no change in atomic structure and a new substance is not created
Physical change
A ___ happens when the atomic structure of a substance changes, are considered irreversible and a new substance is formed
Chemical change
There are several signs of a chemical change includes:
Formation of gas
Change in colour
Change in PH
Change in temperature
Formation of new solid or liquid
Appearance of light
Production of electricity
Benedict test for the presence of simple sugars is ___
Carbohydrates
Starch- Iodine test
Positive result shows the existence of starch when a ___ tint appears
Blue-black or purple
Starch- Iodine test
Negative result ;
No color change (brown/yellow)
Starch- Iodine test
Basis of positive result;
Long chain of polysaccharide traps the iodine
STARCH -Iodin test
Basis of negative result;
Brown color remains monosaccharides unable to trap iodine
SUGARS- BENEDICT TESTA
Positive result;
Green to dark red/ rusty brown
SUGARS. -BENEDICT TEST
Negative result;
No color change (blue)
___ is a simple carbohydrates with a free aldehyde or ketone group and acts as a reducing agent
Reducing sugar
Simple carbohydrates
Benedicts solution
SUGAR TEST
Simplest unit of carbohydrates
Monosaccharides
SUGAR TEST
Made by linking monosaccharides
Disaccharides
SUGAR TEST
complex carbohydrates
Iodine solution
SUGAR TEST
Starch cellulose, glycogen
Polysaccharide
PROTEIN- BIURET TEST
Biuret reagent ;10% ___, 0.5% ____
Sodium hydroxide
Copper sulfate
PROTEINS - BIURET TEST
positive result ;
• shows the existence of peptides when the color of the solution changes to ___
Purple
Pink
PROTEINS - BIURET TEST
Negative result;
-Lack of protein
No color change (blue)
Determines the presence of lipids ,
A fat soluble dye that stains lipids red
Sudan III or IV
LIPIDS- SUDAN III OR IV
positive result;
Has 2 layer
Top layer is (red/orange)
LIPIDS- SUDAN III OR IV
Negative result;
Clear solution or
1 layer is red/ orange
Number of times an object is enlarged or reduced
Magnification
Combination of magnification of objectives and the eyepiece
Total magnification
How many times is an image enlarged?
Scanner =
LPO =
HPO =
Eyepiece =
4x
10x
40x
10x
Combination of eyepiece and an objective
Eyepiece and scanner=
Eyepiece and LPO =
Eyepiece and HPO =
40x
100x
400x
PARTS OF A MICROSCOPE AND ITS FUNCTION
Mechanical
Diopter adjustment
Body tube
Arm
Stage
Revolving nose piece
Coarse adjustment knob
Fine adjustment knobs
PARTS OF A MICROSCOPE AND ITS FUNCTION
Optical
Ocular lense
Objectives (Scanner, Low power, high power, Oil immersion objectives)
PARTS OF A MICROSCOPE AND ITS FUNCTION
Illuminating
Light source
Condenser
Iris diaphragm
“pro” means -
Has a rigid cell wall
No membrane bound organelles
Before
Prokaryotic cells
“eu” mean -
Has a membrane bound organelles
True
Eukaryotic cells
KEY DIFFERENCE PLANT VS ANIMAL
Animals cells have a ___ and ___ whereas plant cells do not
Centrosome
Lysosomes
The lysosomes are the animal garbage disposal while in plant cells the same function takes place in __
Vacuoles
The ____ plays a key role in regulating a plant cells concentration of water in changing environment conditions
Central vacuole
___is made up of scally leaves which store starch granules in their cytoplasm of the cells
Onion bulb
CELL ACTIVITY
___ binds to starch in the granules and develops blue-to black color
Iodine
CELL ACTIVITY
Onion stores reserve food material in the form of ___
Starch
CELL ACTIVITY
___ stains negatively charged molecules in the cell
Methylene blue
CELL ACTIVITY
The small blue dots are ___ from our teeth and mouth
Bacteria
Directed flow of cytosol and organelles around the plant cells, help in the Transport of organelles, nutrients, genetic information, metabolites and other materials
Cytoplasmic streaming
UNIT CONVERSION
1mm =
1000 um
Intelligent education guess to a certain problem
Hypothesis
Overall statement which provides basis for prediction
Descriptive hypothesis
Statement tend to guess what caused the pattern
Explanatory hypothesis
Example of compound microscope
Darkfield
Phase contrast
Electron
Dissecting