【GR1724】 The Solution for GRE Biology Practice Test [180-194]

The Solution for GRE Biology Practice Test [180-194]

 

추천글 : 【GRE】 Solution for GRE Biology Practice Test 

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Questions 180-181 

The following experiment is designed to study the role of several hormone in the regulation of metamorphosis in frogs.

 

 

Groups consisting of 10 frog tadpoles (all in the same developmental stage) were injected with one of several solutions or else had their thyroid glands removed (treatments) and the time until final tail reabsorption was measured. The experiment was terminated at 100 days. The hormones used were from one of three glands: the pituitary gland (prolactin and TSH-thryoid stimulating hormone), the thyroid gland (thyroxine), or the adrenal glands (corticosterone). The only known endogenous action of TSH is to stimulate thyroid gland secretions.

 

180. If the thyroid gland were removed from the tadpoles in Group 3 

 

 

⑴ answer: E

⑵ the same condition with Group 8

⑶ Thyroid hormones may affect the days to metamorphosis.

 

 

181. These results suggest which of the following about prolactin at the dose tested?

 

 

⑴ answer: B

 

 

Questions 182-185

The MacArthur-Wilson equilibrium model of island biogeography predicts the number of species found on islands. The figure below depicts two volcanic islands located off a section of mainland coast.

 

 

182. The MacArthur-Wilson model predicts that the relative numbers of bird species on the mainland and two islands would be 

 

 

⑴ answer: B

 

 

183. According to the MacArthur-Wilson model, how would the number of bird species change from the time of an island's formation (assuming it remains constant in size and isolation)?

 

 

⑴ answer: E

 

 

184. According to the MacArthur-Wilson model, the number of bird species present on Island 2 at any one time is a function of the relative rates of 

 

 

⑴ answer: B

 

 

185. If a drop in sea level led Island 1 to double in area, the MacArthur-Wilson model predicts that the number of bird species found there would 

 

 

⑴ answer: D

 

 

Questions 186-188 refer to the following pedigree for the inheritance of a very rare human disease over three generations.

 

 

186. Which of the following is the most likely mode of inheritance for the disease trait? 

 

 

⑴ answer: D

⑵ cytoplasmic : Wrong, because of Ⅱ-5 and Ⅲ-7.

⑶ X-linked recessive : If Ⅰ-2 is X'X', Ⅰ-1 is X'Y due to Ⅱ-1 and Ⅱ-5. However, Ⅰ-1 should be XY in this case.

⑷ Y-linked dominant : If Ⅰ-1 is XY, Ⅱ-3 cannot be X'Y.

⑸ autosomal dominant : Ⅰ-2, Ⅱ-1, Ⅱ-3, Ⅱ-5, Ⅲ-3, Ⅲ-6, and Ⅲ-8 can be AA' equally. 

⑹ genetic imprinting : A phenomenon in which the phenotype changes depending on which of the parents one received the trait from.

 

 

187. If individual Ⅲ-3 were to have a daughter, what is the probability that the daughter would receive the disease trait from her mother (Ⅲ-3)?

 

 

⑴ answer: B

⑵ As Ⅲ-3 is AA', such a probability should be 50%.

 

 

188. If individuals Ⅲ-3 and Ⅲ-6 were to produce a son, what is the probability that the son would be affected with the disease?

 

 

⑴ answer: B

⑵ Ⅲ-3 : AA'

⑶ Ⅲ-6 : AA' 

⑷ Pr = 1 - 0.5 × 0.5 = 0.75 

 

 

Questions 189-191

According to the ABC model of flower development in Arabidopsis, three classes of organ identity genes - designated A, B, and C - are required to specify the identity of floral organs in each whorl of a flower. As shown in the figure below, expression of A class genes alone in the first (outermost) whorl specifies sepals; expression of A and B class genes in the second whorl specifies petals; expression of B and C class genes in the third whorl specifies stamens; and expression of C class genes alone specifies carpels. 

 

A and C class genes restrict each other's expression. Null mutations in A class genes lead to expression of C class genes in all four whorls, whereas null C class mutations result in expression of A class genes in all whorls.

 

 

189. If wild type Arabidopsis were transformed with a chimeric gene composed of a C class promoter fused to a B class coding sequence, which of the following arrangements (outer to inner) would be predicted?

 

 

⑴ answer: A

⑵ A only → A only (Se)

⑶ A + B → A + B (Pe)

⑷ B + C → B + C (St)

⑸ C → B + C (St)

 

 

190. An Arabidopsis line that produced flowers with carpel identity in all four whorls would most likely have mutation(s) in 

 

 

⑴ answer: D

 

 

191. According to the ABC model, which of the following arrangements of floral organs (from outermost to innermost whorl) would be predicted for a null mutation in a B class gene?

 

 

⑴ answer: B

⑵ A only → A only (Se)

⑶ A + B → A only (Se)

⑷ B + C → C only (Ca)

⑸ C only → C only (Ca)

 

 

Questions 192-194

The following figure is a model of seedling establishment as a function of distance from a parent tree. Initial seed density measures the number of seeds falling to the ground. Seed survivorship measures the proportion of seeds that survive to the adult stage at each distance. 

 

 

192. This model predicts that recruitment of new individuals into the population should be 

 

 

⑴ answer: B

⑵ a tradeoff

 

 

193. Which of the following factors is most likely to generate the seed density curve shown?

 

 

⑴ answer: B

 

 

194. Which of the following factors is most likely to generate the seed survivorship curve shown?

 

 

⑴ answer: A

 

입력: 2023.05.30 01:08