Which of the following properties does soap, an emulsifier, have that make it useful for washing dirt off one’s hands with water?
A. Soap’s dual polar and nonpolar nature helps bond oil and water
B. Soap’s acidity causes grime to precipitate into the water
C. Soap’s enzymatic action helps to dissolve grime into small particles
D. Soap’s rough texture physically scours grime off surfaces
The correct answer is a. Soap’s dual polar and nonpolar nature helps bond oil and water. Soap is an emulsifier, which means that it has both polar and nonpolar regions. The polar regions of soap molecules are atracted to water, while the nonpolar regions are atracted to oil and grease. This allows soap to bond with both water and oil, helping to remove dirt and grime from surfaces.
B. Soap’s acidity does not cause grime to precipitate into the water.
C. Soap does not have enzymatic action that helps to dissolve grime into small particles.
D. Soap’s texture does not physically scour grime off surfaces.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: If a portion of a strand of DNA bases reads 3’TCGATCGCA 5’, what would the sequence of bases on the complementary strand read?
A. 5’AGCTAGCGT 3’
B. 3’ TCGUTCGCU 5’
C. 3’ AGCTAGCGT 5’
D. 5’ GGUTACTAC 3’
Answer Explanation
The sequence of bases on the complementary strand of DNA would read 5’AGCTAGCGT 3’ (Choice A). In DNA, the nitrogenous bases adenine (A) and thymine (T) pair together, and cytosine (C) and guanine (G) pair together. The complementary strand is also antiparallel to the original strand, meaning that it runs in the opposite direction with the 5' end matching up with the 3' end of the original strand.
The other options do not accurately represent the complementary sequence of bases or the antiparallel orientation of the strands.
BONUS:
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Q #2: Punnet Square An organism with an unknown genotype is crossed with another organism that shows the recessive trait (aa). The Punnet square below shows the results. Which of the following is the unknown genotype? Unknown Unkonwn a Aa aa a Aa aa
A. a
B. Aa
C. aa
D. AA
Answer Explanation
The unknown genotype is Aa. This can be inferred from the Punnet square, which shows that half of the offspring are Aa and half are aa. This indicates that the unknown parent must have one dominant allele (A) and one recessive allele (a), making its genotype Aa.
The other options are not correct because they do not match the results shown in the Punnet square. If the unknown genotype was aa or AA, all of the offspring would have the same genotype as their parent. If the unknown genotype was a, it would not be a valid genotype as it only has one allele.
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Q #3: Parasitic worm infestation is hypothesized to be damaging to the host. However, scientists have recently discovered that worm infestation can relieve the effects of certain autoimmune disorders. In which of the following ways should the hypothesis be modified, given the new findings?
A. Worm infestation prevents the body from immune malfunction.
B. Worm infestation reduces the severity of certain autoimmune disorders.
C. Lack of worm infestations is the cause of some autoimmune disorders.
D. Worm infestations exacerbate the body's immune reaction.
Answer Explanation
Given the new findings that worm infestation can relieve the effects of certain autoimmune disorders, the hypothesis should be modified to state that worm infestation reduces the severity of certain autoimmune disorders.
This option best reflects the new information and suggests a potential benefit of worm infestation in relation to autoimmune disorders. The other options do not accurately reflect the new findings and do not provide a clear modification to the hypothesis.
