【GR1724】 The Solution for GRE Biology Practice Test [61-80]

The Solution for GRE Biology Practice Test [61-80]

 

추천글 : 【GRE】 Solution for GRE Biology Practice Test 

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61. Which of the following is a correct statement about the cohesion-tension theory for the ascent of water in the xylem?

 

 

⑴ answer: A

⑵ Transpiration occurs in leaves, and then evaporation reoccurs with strong cohesive neighboring water molecules.

 

 

62. A transverse section of a leaf is represented in the diagram above. Transpiration in the leaf depends on the transport of potassium ions

 

 

⑴ answer: B

⑵ The higher the K⁺ and Cl^- content in the guard cell, the greater the pressure of the guard cell, making the larger stomate.

 

 

63. Which of the following is the symplastic pathway for the movement of sucrose from the site of photosynthesis in mesophyll into the phloem?

 

 

⑴ answer: D

 

 

64. In plants, proton pumps are involved in the process of loading sugars into the phloem for transport. Which of the following is true about this process?

 

 

⑴ answer: C

⑵ ATP is required because sugar should be transported against concentration from donor (production) to recipient (demand).

 

 

65. According to the pressure-flow model of movement of phloem contents, photosynthate movement from source to sink is driven by

 

 

⑴ answer: B

⑵ water movement = physical + chemical + biological 

⑶ physical water movement = water potential = water-pressure potential gradient + concentration potential gradient

⑷ pressure-flow = water-pressure potential gradient

⑸ Transpiration is a concerted water movement with water-pressure and concentration potential gradient.

 

 

66. All of the following statements about plant embryogenesis are correct EXCEPT: 

 

 

⑴ answer: C

 

 

67. In an experiment, a plant cell was placed into a medium containing a 1.0 mM concentration of Ca²⁺. The electrochemical potential across the plasma membrane was measured at -110 mV. The Nernst equation predicted that the intracellular concentration of Ca²⁺ would be 5,400 mM. The actual concentration of Ca²⁺ in the cell was 1.5 mM. This value suggests that calcium

 

 

⑴ answer: D

⑵ Nernst equation assumes an equilibrium between electric potential and concentration potential.

⑶ If an active mechanism is pushing intracellular Ca²⁺ ions out of the cell, the overall force driving these ions out could be larger than expected, leading to an overestimation of the concentration potential, which is proportional to the difference between intracellular and extracellular Ca²⁺ ions.

 

 

68. Which of the following statements about fungi is NOT true?

 

 

⑴ answer: D

⑵ Fungi has no chloroplast, so it cannot photosynthesize.

 

 

69. Barley seeds are divided in half, as shown in the diagram below, and the halves containing only endosperm and aleurone are then treated with different concentrations of gibberellin. After 8 hours of incubation, reducing sugars appear and a calibration curve is developed for the relation between gibberellin concentration and the production of reducing sugars. The most important reason for removing the embryo of the seeds used in the experiment is to 

 

 

⑴ answer: C 

 

 

70. Which of the following would be the most dependable environmental signal that a plant in a temperate ecosystem could use to initiate flowering at the correct time of the year?

 

 

⑴ answer: B

⑵ flowering and night time 

 

 

71. Which of the following is a benefit that mycorrhizal fungi confer to many plants?

 

 

⑴ answer: C

 

 

72. Short-term changes in plant growth rate mediated by the plant hormone auxin are hypothesized to result from 

 

 

⑴ answer: B

⑵ general information of auxin

 

 

73. A prokaryote that is thermophilic and methanogenic and has isoprenylglycerol ethers in its membrane instead of phospholipids is most likely

 

 

⑴ answer: D

⑵ general information of archaeon

 

 

74. Antibiotics that affect bacterial cells interfere with all of the following EXCEPT

 

 

⑴ answer: D

⑵ Molecules targeting reverse transcriptases are only valid for viruses.

 

 

75. Which of the following characteristics distinguishes angiosperms from gymnosperms?

 

 

⑴ answer: D

 

 

76. In fungi, cell walls are reinforced by which of the following?

 

 

⑴ answer: A

⑵ general information of chitin 

 

 

77. Ferns undergo alternation of generations in which a 

 

 

⑴ answer: A

 

 

78. Mammals are homeostatic for all of the following EXCEPT

 

 

⑴ answer: D

⑵ homeostasis

⑶ Metabolic rates can be enhanced by exercise.

 

 

79. Which of the following statements is true of air as compared to water?

 

 

⑴ answer: B

 

 

80. Which of the following is a reason that geneticists use mitochondrial DNA (mtDNA) to study the relatedness of animal populations?

 

 

⑴ answer: B

⑵ mtDNA is remarkable in that it is well-conserved evolutionarily and transmitted by maternal inheritance. 

 

입력: 2023.05.12 00:06