What is the normal flora?
A. A variety of microbial species found in certain areas of the human body.
B. A group of infectious parasites that cause diarrheal diseases.
C. The genetic material of bacteria housed within a true nucleus.
D. The protein coat surrounding the viral genome.
The normal flora refers to the microbial community that colonizes on the skin and mucus membrane .
Normal flora can be found in many sites of the human body including the skin, respiratory tract, urinary tract, and the digestive tract.
Choice B is incorrect because normal flora does not refer to a group of infectious parasites that cause diarrheal diseases .
Choice C is incorrect because normal flora does not refer to the genetic material of bacteria housed within a true nucleus .
Choice D is incorrect because normal flora does not refer to the protein coat surrounding the viral genome .
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: Which of the following is a consequence of increased viscosity of a fluid?
A. Particles have a decrease in mobility.
B. The fluid will have a lower density.
C. The fluid will have a higher flow rate.
D. The fluid will have a higher pressure.
Answer Explanation
The correct answer is choice A.
An increase in viscosity of a fluid results in a decrease in mobility of particles.
Viscosity is the resistance of a fluid to a change in shape or movement of neighboring portions relative to one another.
It denotes opposition to flow and may be thought of as internal friction between the molecules.
Choice B is incorrect because an increase in viscosity does not affect the density of a fluid.
Choice C is incorrect because an increase in viscosity results in a decrease, not an increase, in flow rate.
Choice D is incorrect because an increase in viscosity does not affect the pressure of a fluid.
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Q #2: What is hydrogen bonding?
A. The attraction between the relatively positive areas of one molecule and the relatively negative areas of another molecule.
B. The repulsion between the positive and negative charges of two molecules.
C. The attraction between two nonpolar molecules.
D. The attraction between two ionic molecules.
Answer Explanation
Hydrogen bonding is an interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons.
One atom of the pair (the donor), generally a fluorine, nitrogen, or oxygen atom, is covalently bonded to a hydrogen atom, whose electrons it shares unequally; its high electron affinity causes the hydrogen to take on a slight positive charge.
The other atom of the pair (the acceptor), also typically F, N, or O, has an unshared electron pair, which gives it a slight negative charge.
Mainly through electrostatic attraction, the donor atom effectively shares its hydrogen with the acceptor atom, forming a bond.
Choice B) The repulsion between the positive and negative charges of two molecules is incorrect because hydrogen bonding involves attraction, not repulsion.
Choice C) The attraction between two nonpolar molecules is incorrect because hydrogen bonding involves polar molecules.
Choice D) The attraction between two ionic molecules is incorrect because hydrogen bonding involves polar molecules and not ionic molecules.
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Q #3: Which of the following statements about bacteria and archaea is true?
A. A. Bacteria have a true nucleus while archaea do not
B. B. Archaea reproduce by spores while some bacteria reproduce by fission.
C. C. Bacteria can perform photosynthesis while archaea cannot.
D. D. Archaeal and bacterial flagella are constructed similarly.
Answer Explanation
Bacteria can perform photosynthesis while archaea cannot. Many types of bacteria can generate oxygen from sunlight through photosynthesis, while archaea cannot perform this process.
Choice A is incorrect because neither bacteria nor archaea have a true nucleus. Both are prokaryotic organisms. Choice B is incorrect because archaea reproduce by fission, fragmentation, or budding, while bacteria can produce spores and divide sexually or asexually. Choice D is incorrect because archaeal and bacterial flagella are constructed differently.
