Nokea
Which of the following is not an RNA base?
- A. Adenine
- B. Thymine
- C. Uracil
- D. Cytosine
Correct Answer: B
Rationale: In RNA, the bases are Adenine, Uracil, and Cytosine. Thymine is uniquely found in DNA and not RNA. Adenine pairs with Uracil, while Cytosine pairs with Guanine in RNA. Thus, Thymine is not an RNA base, making it the correct answer.
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Which of the following statements about antibiotics is not true?
- A. They can interfere with the bacteria's ability to survive
- B. They can affect how bacteria multiply
- C. They can cause more bacteria to grow
- D. They only work on bacteria
Correct Answer: C
Rationale: Antibiotics are medications used to treat bacterial infections by either killing the bacteria or inhibiting their growth. Options A and B correctly describe the mechanisms of action of antibiotics, making them true statements. Option C is incorrect as antibiotics are meant to reduce bacterial growth, not cause more bacteria to grow. Option D is also true as antibiotics specifically target bacterial infections and do not work on viruses or other pathogens.
What type of bond holds water molecules together?
- A. Ionic
- B. Covalent
- C. Hydrogen
- D. Molecular
Correct Answer: C
Rationale: The correct answer is 'Hydrogen.' Water molecules are held together by hydrogen bonds. These bonds form between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another water molecule. While hydrogen bonds are weaker than covalent bonds, they play a crucial role in various biological processes, such as the cohesion of water molecules and the unique properties of water as a solvent.
Which is an example of the comet organizational hierarchy for a wolf?
- A. Muscle tissue, blood cell, DNA, organ, circulatory system, wolf.
- B. Circulatory system, DNA, muscle tissue, blood cell, heart, wolf.
- C. Blood cell, organ, circulatory system, muscle tissue, DNA, wolf.
- D. DNA, blood cell, muscle tissue, heart, circulatory system, wolf.
Correct Answer: D
Rationale:
What cellular appendage enables cells to move through their environments?
- A. Flagellum
- B. Cell membrane
- C. Transport protein
- D. Receptor
Correct Answer: A
Rationale: The flagellum is a whip-like appendage found in certain cells like sperm cells and some bacteria, enabling them to move through their environments. It plays a crucial role in locomotion by allowing cells to swim or propel themselves in liquids, aiding in their movement and navigation.
Which of the following is a benefit of the intermolecular hydrogen bonding of water? (Select one that doesn't apply.)
- A. Water has a relatively high specific heat value.
- B. Water has strong cohesive and adhesive properties.
- C. Polarity of water allows it to act as a versatile solvent.
- D. Water moves from higher to lower concentrations.
Correct Answer: D
Rationale: Intermolecular hydrogen bonding in water leads to various unique properties. Options A, B, and C are benefits of this bonding. Water's high specific heat value allows it to resist temperature changes, which is advantageous for temperature regulation in organisms. The strong cohesive and adhesive properties of water contribute to capillary action and surface tension, essential in biological systems. Additionally, water's polarity enables it to dissolve a wide range of substances, making it a versatile solvent. Option D, 'Water moves from higher to lower concentrations,' is not a direct benefit of intermolecular hydrogen bonding of water. Instead, it describes the process of osmosis, which is driven by differences in solute concentrations rather than hydrogen bonding.