Bio Lab
What were the conclusions of this experiment? Select all that apply.
two eggs cartons
This image illustrates what correct safety practices? (Select all that apply)
use of gloves and eye protection. tying back of long hair. uncluttered work bench. wearing of the lab coat.
The liter is the metric base unit of measurement for
volume.
In the pillbug experiment, your hypothesis
was related to the environment pillbugs prefer.
Soap should be applied to __________ hands.
wet
Match each item with the correct base unit of the metric system used to measure the item.
powdered chemical - Gram Height of a tree - Meter amount of water in a test tube - Liter heat of a water bath - Temperature
In the weight exercise, the tare button was used to
reset the scale.
In the pillbug experiment, the substance used as the control was
sand.
What instrument did you use to weigh objects in the metric system lab?
scale. A digital scale was used to measure the weight of sodium chloride powder in grams.
In the pillbug experiment, how many pillbugs did you need to use to get good information for the experiment?
10
What is the minimal drying time for the paper lipid test?
15 minutes
A disinfectant is used on your work surface:
All of the answer choices are correct.
The Benedict's test indicates a positive result when the solution turns
All of the choices are correct.
Which factor was changed between each trial?
size of wood pieces
Which of the following are functions of carbohydrates? (Select all that apply)
storage of genetic information. storage of energy. structural support. signaling molecules (such as hormones or neurotransmitters). Carbohydrates primarily function as chemical energy (glucose) within the body; however, some sugars (ribose and deoxyribose) are necessary for structural support within nucleic acids.
Polysaccharides are polymers composed of
sugars.
When biuret reagent is added to a solution containing protein, the solution turns pink or purple. In the absence of protein, the solution is blue. Biuret reagent was added to solutions that may or may not contain protein. The data can be seen in the table below. What is the dependent variable in this experiment?
the color change from blue to purple
Which reagent is used to detect the presence of simple sugars?
Benedict's
Which of the following tests requires heating prior to observing results?
Benedict's test
The formation of an orange or purple color after the addition of iodine indicates that a sample contains lipids.
False
The metric scale of temperature is Fahrenheit.
False. (In the metric system, gram is the base unit for weight, meter is the base unit for length, liter is the base unit for a liquid, and Celsius is the base for temperature.)
You may eat a snack in lab as long as there are no bacterial cultures on your bench and you have thoroughly washed your hands.
False. There should never be food or drink of any kind in the laboratory.
An unknown liquid sample is tested for chemical composition. You receive the following results: iodine test = orange; biuret test = purple; Benedict's test = blue; and paper lipid test = clear. Which of the following are present in this sample? (Select all that apply)
Protein. Sugar. lipids.
A drop of liquid that does not evaporate from brown paper after a 20-minute period at room temperature contains lipids.
True. Lipids evaporate at a much slower rate that polar substances such as water. In addition, they will have a shiny or greasy appearance on brown paper.
When comparing the milligram, gram, microgram, and kilogram, the largest unit of weight is the kilogram.
True. Milligram is 1/1000 the base, gram is the base, microgram is 1/1 million the base and kilogram is 1000x the base therefore kilogram is the largest unit of measurement.
Watches, bracelets, and rings should be removed prior to washing hands.
True. Watches, bracelets, and rings may contain or cover contaminants and interfere with the cleaning process.
The biuret test would indicate a positive result for proteins in which of the following solutions?
albumin solution
Proteins are polymers composed of
amino acids.
When measuring the volume of a liquid in a graduated cylinder, at which point should the measurement be taken?
at the meniscus
When utilizing the scientific method, there are two types of variables. They are
dependent and independent.
The purpose of this experiment was to
determine why cells are small.
In the metric system, the base unit of weight is the
gram
Which factor was being measured in the experiment?
how long it took the wood to completely burn
Which reagent is used to detect the presence of starch?
iodine
Liz is interested in the relative sugar concentration of her favorite sodas. She mixes a standard amount of each soda with a standard amount of the reagent, heats the samples in boiling water for five minutes, and observes the color reactions. Place the soda brands in order of increasing sugar concentration (lowest to highest).
1) Brand D (Blue reaction color) 2) Brand C (Green reaction color) 3) Brand M (Yellow reaction color) 4) Brand X (Red reaction color)
Place the following steps of the hand washing procedure in the correct order.
1) Thoroughly wet hands in running water. 2) Apply soap. 3) Lather for at least 20 seconds by rubbing hands together, paying attention to the back of hands, nails, and between fingers 4) Rinse thoroughly in running water. 5) Dry hands thoroughly and use a towel to turn off the faucet.
How long should hands be lathered while washing?
20 seconds. The Center for Disease Control currently recommends 20 seconds of lathering under running water. This is about how long it takes to sing or hum the "Happy Birthday" song twice.
At room temperature, Biuret reagent should react with protein within
30 seconds.
Why is it important to use the tare function when weighing an object placed in a beaker?
It allows you to weigh the object and disregard the beaker.
Jacob had just finished his lab work and went to the sink to wash his hands. He removed his watch, and added liquid soap to his hands. He then turned on the water and began to rub his hands together, lathering for 20 seconds and cleaning fronts and backs of hands, fingernails, and between his fingers. He then rinsed his hands in running water, dried his hands with paper towels, and used an additional paper towel to turn off the faucet. Which statement is correct?
Jacob should have wet his hands in running water before applying the soap.
In the weight exercise of the metric system lab, what object/materials did you practice weighing?
beaker and salt
Which reagent is used to detect the presence of protein?
biuret
Which color change represents a positive reaction for the presence of sugar using the Benedict's test?
blue to orange
Which of the following tests is used to detect the presence of lipids?
brown paper test
Which of the following are functions of proteins? (Select all that apply)
catalytic (enzymatic) activity. structural support. transport of molecules/ions through blood and across plasma membranes.
In the length unit exercise, what tool did you use to measure the circles?
metric ruler
In which circumstance is food and/or beverage allowed in the laboratory?
never. Food and beverages are NEVER allowed in the laboratory.
According to the results of the pillbug experiment,
pillbugs tend to prefer cornstarch over sand.
When graphing your data, it is important that you
place the independent variable on the X-axis.
