Animal fossils usually provide very little opportunity to study the actual animal tissues, because in fossils the animals' living tissues have been largely replaced by minerals. Thus, scientists were very excited recently when it appeared that a 70-million-year-old fossil of Tyrannosaurus rex (T. rex), a dinosaur, might still contain remains of the actual tissues of the animal. The discovery was made when researchers deliberately broke open the T. rex’s leg bone, thereby exposing its insides to reveal materials that seem to be remains of blood vessels, red blood cells, and collagen matrix.
First, the breaking of the fossilized leg bone revealed many small branching channels inside, which probably correspond to hollows in the bones where blood vessels were once located. The exciting finding was the presence of a soft, flexible organic substance inside the channels. This soft substance may very well represent the remains of the actual blood vessels of T. rex.
Second, microscopic examination of the various parts of the inner bone revealed the presence of spheres that could be the remains of red blood cells. Tests showed that the spheres contained iron-a material vital to the role of red blood cells in transporting oxygen to tissues. Moreover, the spheres had dark red centers (substances with iron tend to be reddish in color) and were also about the size of red blood cells.
Third, scientists performed a test on the dinosaur leg bone that showed that it contained collagen. Collagen is a fibrous protein that is a main component of living bone tissue, in which it forms a so-called collagen matrix. Collagen (or its chemical derivatives) is exactly the kind of biochemical material that one would expect to find in association with bone tissue.
The reading passage argues that the materials found inside a T.rex leg bone are actually remains of blood vessels, red blood cells and collagen from the animal. However, the lecturer, on the other hand, casts doubt on the claims made in the article. He mentions that there are sound reasons to be skeptical about these identifications.
First and foremost, the author contends that the organic substance discovered could be from the blood vessels of T.rex. Nevertheless, the speaker in the lecture challenges this point of view. He holds that bacteria could have colonized the hollow channels and the organic matter is just traces of bacterial colonies.
Secondly, the writer assumes that the spheres unearthed are red blood cells since it contains iron and they are reddish in color. In addition, they are almost the same size of red blood corpuscles. Conversely, the lecturer points out that those objects were also found in primitive animals' fossils at the same site, which are not supposed to have red blood cells when they were alive.
Lastly, the excerpt posits that the confirmation of the presence of collagen proves that the remnants might be of blood vessels. In contrast, the lecturer brings up the fact that the oldest collagen ever detected was from 100,000 year-old fossils. Furthermore, the common belief between scientists is that collagen cannot last longer than that. Hence, the source of this uncovered collagen might be the researchers' skin rather than from the fossil.
- Although most scientists would agree that the Moon is critical for the formation of life on Earth, there is no consensus about the way that the Moon formed. Although there are several additional theories to explain the way that the Moon came into being, t 75
- In 1957 a European silver coin dating to the eleventh century was discovered at a Native American archaeological site in the state of Maine in the United States. Many people believed the coin had been originally brought to North America by European explor 73
- Private collectors have been selling and buying fossils, the petrified remains of ancient organisms, ever since the eighteenth century. In recent years, however, the sale of fossils, particularly of dinosaurs and other large vertebrates, has grown into a 3
- Do you agree or disagree with the following statement? It is more enjoyable to have a job where you work only three days a week for long hours than to have a job where you work five days a week for shorter hours. Use spec 73
- Some students prefer to study at a large university that has several thousand students. Other students prefer studying at a small school that has only a few hundred students. Which type of these two types of schools do you prefer? 60
Grammar and spelling errors:
Line 9, column 113, Rule ID: ADJECTIVE_IN_ATTRIBUTE[1]
Message: A more concise phrase may lose no meaning and sound more powerful.
Suggestion: reddish
...lls since it contains iron and they are reddish in color. In addition, they are almost the same ...
^^^^^^^^^^^^^^^^
Line 9, column 386, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...e red blood cells when they were alive. Lastly, the excerpt posits that the con...
^^^^^^^
Line 13, column 32, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
.... Lastly, the excerpt posits that the confirmation of the presence of coll...
^^
Transition Words or Phrases used:
actually, also, conversely, first, furthermore, hence, however, if, lastly, nevertheless, second, secondly, so, in addition, in contrast, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 15.0 10.4613686534 143% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 4.0 7.30242825607 55% => More conjunction wanted.
Relative clauses : 13.0 12.0772626932 108% => OK
Pronoun: 21.0 22.412803532 94% => OK
Preposition: 30.0 30.3222958057 99% => OK
Nominalization: 4.0 5.01324503311 80% => OK
Performance on vocabulary words:
No of characters: 1265.0 1373.03311258 92% => OK
No of words: 243.0 270.72406181 90% => More content wanted.
Chars per words: 5.20576131687 5.08290768461 102% => OK
Fourth root words length: 3.94822203886 4.04702891845 98% => OK
Word Length SD: 2.49900317135 2.5805825403 97% => OK
Unique words: 147.0 145.348785872 101% => OK
Unique words percentage: 0.604938271605 0.540411800872 112% => OK
syllable_count: 369.0 419.366225166 88% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 3.25607064018 92% => OK
Article: 10.0 8.23620309051 121% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 3.0 2.5761589404 116% => OK
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 18.0 21.2450331126 85% => The Avg. Sentence Length is relatively short.
Sentence length SD: 32.7075982342 49.2860985944 66% => OK
Chars per sentence: 97.3076923077 110.228320801 88% => OK
Words per sentence: 18.6923076923 21.698381199 86% => OK
Discourse Markers: 11.9230769231 7.06452816374 169% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 3.0 4.19205298013 72% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 2.0 4.45695364238 45% => More negative sentences wanted.
Sentences with neutral sentiment: 7.0 4.27373068433 164% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.0714858322967 0.272083759551 26% => The similarity between the topic and the content is low.
Sentence topic coherence: 0.0211177104528 0.0996497079465 21% => Sentence topic similarity is low.
Sentence topic coherence SD: 0.0437571141616 0.0662205650399 66% => OK
Paragraph topic coherence: 0.0378886643345 0.162205337803 23% => Maybe some paragraphs are off the topic.
Paragraph topic coherence SD: 0.0345954862361 0.0443174109184 78% => OK
Essay readability:
automated_readability_index: 12.5 13.3589403974 94% => Automated_readability_index is low.
flesch_reading_ease: 61.67 53.8541721854 115% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.1 11.0289183223 83% => OK
coleman_liau_index: 12.94 12.2367328918 106% => OK
dale_chall_readability_score: 9.01 8.42419426049 107% => OK
difficult_words: 69.0 63.6247240618 108% => OK
linsear_write_formula: 8.0 10.7273730684 75% => OK
gunning_fog: 9.2 10.498013245 88% => OK
text_standard: 13.0 11.2008830022 116% => OK
What are above readability scores?
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It is not exactly right on the topic in the view of e-grader. Maybe there is a wrong essay topic.
Rates: 3.33333333333 out of 100
Scores by essay e-grader: 1.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.