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.
Both the listening and the reading material discuss the T'rex's leg bone recently found. The reading to be more specific, argues that this discovery will provide insights into the remain of blood vessels, red blood cells and collagen matrix. On the contrary, the professor holds a different idea and states that the theories provided by the reading are somewhat skeptical.
The reading begins by stating that, the fossil's holes are likely to be the place where blood vessels once located. However, this is challenged by the professor, who feels strong that these hollows could have been caused from other factors. He further explains that bacteria colonies may have left behind these organic materials.
The reading then points out that the presence of spheres could be the remain of the blood cells. The professor, in contrast, asserts that these spheres can be found on fossils of multiple mammal. He supports his idea by arguing that even mammals who do not posses any blood cells have those same spheres. Thus, this cannot clarify for theory that support the idea of blood cells' presence.
The reading finishes by stating that a test on the bone reveals traces of collagen that may associate with the bone tissue. The lecturer refutes this idea by claiming that the 70- million year- fossil is not able to contain collagen for such a long time. Indeed, collagen is generally thought to be preserve no longer than a few thousands year. Hence, the traces of collagen collected from the fossil could possibly belong to the skin of a researcher.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2018-11-28 | Mohammed AlKhars | 3 | view |
| 2018-11-28 | Mohammed AlKhars | 3 | view |
| 2018-11-28 | Mohammed AlKhars | 3 | view |
| 2018-10-19 | prem123 | 76 | view |
| 2018-10-18 | Munaim Hossain | 90 | view |
- In the United States it had been common practice since the late 1960s no to suppress natural forest fires The let it burn policy assumed that forest fire would burn themselves out quickly without causing much damage However in the summer of 1988 forest fi 48
- You have been told that dormitory rooms at your university must be shared by two students. Would you rather have the university assign a student to share a room with you, or would you rather choose your own roommate? Use specific reasons and details to 93
- A little over 2,200 years ago, the Roman navy attacked the Greek port city of Syracuse. According to some ancient historians, the Greeks defended themselves with an ingenious weapon called a "burning mirror": a polished copper surface curved to focus the 80
- The United Kingdom (sometimes referred to as Britain) has a long and rich history of human settlement. Traces of buildings, tools, and art can be found from periods going back many thousands of years: from the Stone Age, through the Bronze Age, the Iron A 80
- 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 86
Grammar and spelling errors:
Line 1, column 175, Rule ID: A_INFINITVE[1]
Message: Probably a wrong construction: a/the + infinitive
...is discovery will provide insights into the remain of blood vessels, red blood cells and c...
^^^^^^^^^^
Line 5, column 67, Rule ID: A_INFINITVE[1]
Message: Probably a wrong construction: a/the + infinitive
...t that the presence of spheres could be the remain of the blood cells. The professor, in c...
^^^^^^^^^^
Line 7, column 330, Rule ID: POSSESIVE_APOSTROPHE[2]
Message: Possible typo: apostrophe is missing. Did you mean 'thousands'' or 'thousand's'?
Suggestion: thousands'; thousand's
...ght to be preserve no longer than a few thousands year. Hence, the traces of collagen col...
^^^^^^^^^
Line 7, column 402, Rule ID: MAY_COULD_POSSIBLY[1]
Message: Use simply 'could'.
Suggestion: could
...s of collagen collected from the fossil could possibly belong to the skin of a researcher.
^^^^^^^^^^^^^^
Discourse Markers used:
['hence', 'however', 'if', 'may', 'so', 'then', 'thus', 'in contrast', 'on the contrary']
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance in Part of Speech:
Nouns: 0.265734265734 0.261695866417 102% => OK
Verbs: 0.164335664336 0.158904122519 103% => OK
Adjectives: 0.0559440559441 0.0723426182421 77% => OK
Adverbs: 0.0594405594406 0.0435111971325 137% => OK
Pronouns: 0.0104895104895 0.0277247811725 38% => OK
Prepositions: 0.125874125874 0.128828473217 98% => OK
Participles: 0.048951048951 0.0370669169778 132% => OK
Conjunctions: 2.30017686482 2.5805825403 89% => OK
Infinitives: 0.0174825174825 0.0208969081088 84% => OK
Particles: 0.0034965034965 0.00154638098197 226% => OK
Determiners: 0.146853146853 0.128158765124 115% => OK
Modal_auxiliary: 0.027972027972 0.0158828679856 176% => OK
WH_determiners: 0.0174825174825 0.0114777025283 152% => OK
Vocabulary words and sentences:
No of characters: 1551.0 1645.83664459 94% => OK
No of words: 260.0 271.125827815 96% => OK
Chars per words: 5.96538461538 6.08160592843 98% => OK
Fourth root words length: 4.01553427287 4.04852973271 99% => OK
words length more than 5 chars: 0.380769230769 0.374372842146 102% => OK
words length more than 6 chars: 0.296153846154 0.287516216867 103% => OK
words length more than 7 chars: 0.173076923077 0.187439937562 92% => OK
words length more than 8 chars: 0.0692307692308 0.113142543107 61% => OK
Word Length SD: 2.30017686482 2.5805825403 89% => OK
Unique words: 150.0 145.348785872 103% => OK
Unique words percentage: 0.576923076923 0.539623497131 107% => OK
Word variations: 58.9522294571 53.8517498576 109% => OK
How many sentences: 14.0 13.0529801325 107% => OK
Sentence length: 18.5714285714 21.7502111507 85% => OK
Sentence length SD: 19.8464770945 49.3711431718 40% => OK
Chars per sentence: 110.785714286 132.220823453 84% => OK
Words per sentence: 18.5714285714 21.7502111507 85% => OK
Discourse Markers: 0.642857142857 0.878197800319 73% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 4.0 3.39072847682 118% => OK
Readability: 48.1868131868 50.5018328374 95% => OK
Elegance: 1.88059701493 1.90840788429 99% => OK
Coherence and Cohesion:
Essay topic to essay body coherence: 0.233837490702 0.549887131256 43% => OK
Sentence sentence coherence: 0.123319955519 0.142949733639 86% => OK
Sentence sentence coherence SD: 0.0634161970185 0.0787303798458 81% => OK
Sentence paragraph coherence: 0.596821458435 0.631733273073 94% => OK
Sentence paragraph coherence SD: 0.11969778566 0.139662658121 86% => OK
Sentence topic coherence: 0.109510740922 0.266732575781 41% => OK
Sentence topic coherence SD: 0.0448280975781 0.103435571967 43% => OK
Paragraph paragraph coherence: 0.365567255442 0.414875509568 88% => OK
Paragraph paragraph coherence SD: 0.00731974455945 0.0530846634433 14% => Paragraphs are so close to each other.
Paragraph topic coherence: 0.173351413091 0.40443939384 43% => OK
Paragraph topic coherence SD: 0.0131381043291 0.0528353158467 25% => The ideas may be duplicated in paragraphs.
Task Achievement:
Sentences with positive sentiment : 2.0 4.33554083885 46% => OK
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 8.0 4.26048565121 188% => Less neutral sentences wanted.
Positive topic words: 2.0 3.49668874172 57% => OK
Negative topic words: 3.0 3.62251655629 83% => OK
Neutral topic words: 8.0 3.1766004415 252% => OK
Total topic words: 13.0 10.2958057395 126% => OK
What are sentences with positive/Negative/neutral sentiment?
---------------------
Rates: 86.6666666667 out of 100
Scores by essay e-grader: 26.0 Out of 30
---------------------
Note: This is not the final score. 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.