A fertilizer and seed company located in Prince George’s County claims that their fertilizer causes rose bushes to produce more flowers. To support this claim, they set up an investigation. They added the recommended amount of fertilizer to 100 rose bushes in a greenhouse and then counted the number of flowers that bloomed on each bush. The number of flowers on each rose bush ranged from 28 to 36. The average number of flowers on each bush was 33. A gardener was skeptical of the company’s claim. Which statement provides the best reason to be skeptical about this investigation?
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5 points
The sample size was too small to be valid.
The investigation tested only one variable.
The investigation was conducted without a control.
The investigation was conducted only on rose plants.
Intestinal lactase deficiency leads to lactose maldigestion which subsequently can lead to lactose intolerance, i.e. causing clinical symptoms. Infants and children normally express sufficient lactase levels and do not experience clinical symptoms. Overall, adults can be classified as individuals who are lactase persistent or lactose intolerant. The graph below shows the percent of people who are lactose intolerant in various countries. What is the approximate percentage of individuals who are lactase persistent in the US?
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5 points
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45-50%
80-90%
10-15%
30-35%
In your family, lactose intolerance is very common. At a recent holiday holiday gathering (reunion), you noticed that several family members were using the bathrooms after dinner. What part of the scientific process is this?
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5 points
conclusion
hypothesis
observation
experimenting
Knowing that your family members are lactose intolerant, you presume that they may have eaten food containing dairy products at the party. What part of the scientific process is this?
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5 points
conclusion
hypothesis
observation
experimenting
Based on the data, which food do you think caused stomach upset (malestar) of some family members in the gathering (reunion) to use the bathroom after dinner?
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5 points
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bread
carrots
green beans
macaroni & cheese
A researcher is comparing fatty acid molecules with that of amino acid molecules. Which of these statements is true about amino acids, but NOT about fatty acids?
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5 points
always contain carbon
always contain oxygen
always contain nitrogen
always contain hydrogen
You and a partner have brainstormed a design for an implanted device to help keep insulin levels in check for a person who is diabetic. What should be the next step in the design process?
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5 points
Test on a patient
Build a prototype
Revise the design
Evaluate the design
A transportation engineer involved in designing a traffic light system for an intersection is most likely to conduct a vehicle count at the intersection during which of the following stages of the engineering design process?
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5 points
gathering information
analyzing the solution
generating multiple solutions
selecting an appropriate solution
Atoms connected by covalent bonds share ____________.
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5 points
hydrogen ions
ionic compounds
pairs of electrons
carbon and oxygen
Which element are many of the molecules composing living things based on?
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5 points
carbon
iron
nitrogen
potassium
The diagram shows the particles that make up an atom. What is the name of the negatively charged particles shown in this model of an atom? Choose the correct answer.
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5 points
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prions
protons
neutrons
electrons
Which of these describes the structure of a nucleic acid? Select the correct answer.
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5 points
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a long chain of monosaccharides
a chain of monomers composed of a sugar, a phosphate group and a base
several fatty acids linked together
a hydrophilic head containing a glycerol and two hydrophobic tails
Which of these describes a polymer? Choose the correct answer.
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5 points
a large molecule made of smaller subunits
a molecule with a polar head and nonpolar tails
a moleculecomposed of hydrogen, carbon and oxygen
a molecule that catalyzes a reaction in living organisms
What substance is composed on only one type of atom?
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5 points
cell
element
water
compound
Which of these includes sugars and starches?
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5 points
proteins
carbohydrates
phospholipids
unsaturated fatty acids
What is the main function of phospholipids in a cell?
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5 points
produce energy for the cell
contain genetic information
form the cell membrane
increase the rate of reactions
Based on evidence from the images, which statement about the bonding of carbon atoms is NOT true?
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5 points
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Carbon has the ability to form up to four bonds.
Carbon containing compounds must contain double bonds.
Carbon has the ability to bond with other atoms besides carbon.
Carbon atoms can sometimes form ring structures when they bond.
The image below represents: _______________ because a double bond is present between the carbon atoms.
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5 points
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unsaturated fat
saturated fat
What is the name for the basic building blocks of polymers?
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5 points
proteins
macromolecules
monomers