【OG24-591题】The second paragraph in the passage serves primarily to_mofa留学圈mofaGRE在线题库系统_GRE在线搜题_GRE题库解析_GRE真题机经_GRE课程_GRE培训机构

最新题目

题目内容

纠错

Conodonts, the spiky phosphatic remains (bones and teeth composed of calcium phosphate) of tiny marine animals that probably appeared about 520million years ago, were once among the most controversial of fossils. Both the nature of the organism to which the remains belonged and the function of there mains were unknown. However,since the 1981 discovery of fossils preserving not just the phosphatic elements but also other remains of the tiny soft-bodied animals (also called conodonts) that bore them, scientists' reconstructions of the animals' anatomy have had important implications for hypotheses concerning the development of the vertebrate skeleton.

The vertebrate skeleton had traditionally been regarded as a defensive development, champions of this view postulating that it was only with the much later evolution of jaws that vertebrates became predators. The first vertebrates,which were soft-bodied, would have been easy prey for numerous invertebrate carnivores, especially if these early vertebrates were sedentary suspension feeders. Thus, traditionalists argued, these animals developed coverings of bony scales or plates, and teeth were secondary features, adapted from the protective bony scales. Indeed, externa! skeletons of this type are common among the well-known fossils of ostracoderms, jawless vertebrates that existed from approximately 500 to 400 million years ago.However,other paleontologists argued that many of the definitive characteristics of vertebrates, such as paired eyes and muscular and skeletal adaptations for active life, would not have evolved unless the first vertebrates were predatory. Teeth were more primitive than external armor according to this view, and the earliest vertebrates were predators.

The stiffening notochord along the back of the body, V-shaped muscle blocks along the sides, and posterior tail fins help to identify conodonts as among the most primitive of vertebrates. The lack of any mineralized structures apart from the elements in the mouth indicates that conodonts were moreprimitive than the armored jawless fishes such as the ostracoderms. It now appears that the hard parts that first evolved in the mouth of an animal improved its efficiency as a predator, and that aggression rather than protection was the driving force behind the origin of the vertebrate skeleton.

The second paragraph in the passage serves primarily to

outline the significance of the 1981 discovery of conodont remains to the debate concerning the development of the vertebrate skeleton contrast the traditional view of the development of the vertebrate skeleton with a view derived from the 1981 discovery of conodont remains contrast the characteristics of the ostracoderms with the characteristics of earlier soft-bodied vertebrates explain the importance of the development of teeth among the earliest vertebrate predators present the two sides of the debate concerning the development of the vertebrate skeleton

正确答案： E

参考解析

提交我的解析

文章大意逻辑
文章开篇介绍牙形石（Conodonts）曾是最具争议的化石之一，因其所属生物性质和化石功能未知。1981年发现的化石不仅保留了磷酸盐元素，还包括软组织动物遗迹，这对脊椎动物骨骼发育假说有重要意义。接着第二段阐述关于脊椎动物骨骼发育的两种观点：传统观点认为脊椎动物骨骼是防御性发展，先有骨质鳞片或板的覆盖，牙齿是次要特征；另一种观点则认为最早的脊椎动物是掠食性的，牙齿比外部装甲更原始。 文章类型及逻辑简图
文章类型：新旧观点对比 逻辑简图 P1：Conodonts were controversial fossils. 1981 discovery had implications for vertebrate skeleton development hypotheses. P2：Traditional view: vertebrate skeleton as defensive development. Another view: earliest vertebrates were predators. 做题方法及问题类型
这是一道功能题，通过定位到第二段，分析该段在文章中的作用来解题。 选项分析
A选项：概述1981年牙形石遗迹发现对脊椎动物骨骼发展争议的意义。第二段重点在阐述两种观点，而非此发现的意义，该选项错误。 B选项：对比脊椎动物骨骼发展的传统观点和从1981年牙形石遗迹发现得出的观点。第二段未提及从1981年发现得出的观点，只是阐述传统和另一种观点，该选项错误。 C选项：对比ostracoderms和早期软体脊椎动物的特征。第二段重点不在对比两者特征，该选项错误。 D选项：解释最早脊椎动物掠食者牙齿发展的重要性。第二段不是主要解释牙齿发展重要性，该选项错误。 E选项：呈现关于脊椎动物骨骼发展争议的两个方面。符合第二段内容，该选项正确。

题目讨论 (如果对题目有任何的疑惑，欢迎在这里提出来，大家会帮你解答的哦~)

还没有人评论,赶快抢个沙发~

做题笔记

参考解析

题目讨论 (如果对题目有任何的疑惑，欢迎在这里提出来，大家会帮你解答的哦~)

请选择错误类型：

请描述一下这个错误：