--- title: How old is it? Rock layers, rock clocks, amber and the long story of… — how Mova does on the tests · Biology description: Lesson 276 of the biology course of Mova's primary school: 4 of 11 tests right, exam 0 of 4, every question with the options, the student's choice, the right answer and why it chose. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/school-run/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/) [home](https://md.mova.elamur.ai/free/en/) / [at school](https://md.mova.elamur.ai/free/en/school-run/) / [Biology](https://md.mova.elamur.ai/free/en/school-run/biology/) / 276 # How old is it? Rock layers, rock clocks, amber and the long story of life **Tests:** 4 of 11 right · **Exam:** 0 of 4 right · **Kind:** ★ · **Understood:** 9 of 15 · **Run:** 2026-10-18, commit `f3c23ea72` Lesson 276 of the biology course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: [the lesson in the corpora](https://md.mova.elamur.ai/free/en/corpora/school/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/). Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/). ### Test 1 · ★ · wrong ✗ {#t1} In Jurassic Park, scientists take dinosaur blood from a mosquito in amber and make new dinosaurs. Why can't this really happen? - **1.** Mosquitoes did not bite dinosaurs, because dinosaur skin was far too thick for them — **← Mova's choice** · score 3 - **2.** DNA breaks down long before 66 million years, and no dinosaur DNA has been found — **✓ the right answer** · no support - **3.** Amber is too hard to cut — no support - **4.** Dinosaurs had no blood — no support **Why:** It took the question to ask why something happens (its cause). It chose option 1 with score 3, the only option with support. Its support: lesson 37, line 14: «Only female mosquitoes bite, to get protein for their eggs; the itch is your body reacting to the mosquito's spit, and they find people in the dark by sensing…», reached through the option's own match among the sentences about the question's things. What matched: the same action «bite» (+4). Against it: one says «not», the other does not (counts against) (-1). The right option, 2, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t1/) ### Test 2 · ★ · right ✓ {#t2} «my uncle says they carbon dated a T. rex, that's how they know it's 66 million» What is right? - **1.** Yes, carbon dating works for anything, however old it is, so it works on T. rex bones — no support - **2.** No, carbon dating reaches only about 50,000 years; dinosaurs are dated by other rock clocks — **← Mova's choice** · **✓ the right answer** · score 9 - **3.** No, dinosaurs can't be dated at all — no support - **4.** Yes, but only for teeth — no support **Why:** It took the question to ask what something is like. It chose option 2 with score 9, the only option with support. Its support: lesson 271, line 14: «Scientists track big asteroids, and none of the known large ones will hit Earth in the next hundred years.», reached through the same lesson line as the sentence the question matched. What matched: the same action «hit» (+4); it fills the role the question asks for (+3); the same property (+1); a different doer (counts against) (+1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t2/) ### Test 3 · ★ · wrong ✗ {#t3} A fossil lies between a layer of ash 67 million years old below and one 65 million years old above. How old is the fossil? - **1.** Exactly 132 million years — **← Mova's choice** · score 4 - **2.** Older than 67 million years — score 4 - **3.** Between 65 and 67 million years — **✓ the right answer** · score 4 - **4.** Younger than 65 million years — score 4 **Why:** It took the question to ask what something is like. It chose option 1 with score 4, tied with another option at 4 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 275, line 10: «Far fewer than one in a million animals becomes a fossil, because most bodies are eaten, rot or are broken up; only a quick burial without air gives a chance.», reached through the option's own match among the sentences about the question's things. What matched: the same circumstance (+4). The right option, 3, scored 4. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t3/) ### Test 4 · ★ · wrong ✗ {#t4} «found a shell on a mountain, someone must've dropped it from a picnic» What is more likely? - **1.** A seagull carried it all the way up there from the beach — no support - **2.** It grew there on its own — no support - **3.** The mountain was a beach last year — **← Mova's choice** · score 5 - **4.** The rock formed under the sea long ago and was pushed up — **✓ the right answer** · no support **Why:** It took the question to ask which statement is true. It chose option 3 with score 5, the only option with support. Its support: lesson 276, line 16: «Sea fossils are found at the top of Mount Everest, because that rock formed under the sea and was pushed up as continents collided; mountains still rise a few…», reached through the option's own match among the sentences about the question's things. What matched: the same doer «mountains» (+3); the same property (+3). Against it: a different thing acted on (counts against) (-1). The right option, 4, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t4/) ### Test 5 · ★ · wrong ✗ {#t5} Count them: a trilobite fossil shows 5 pairs of jointed legs. How many legs is that? - **1.** 12 — **← Mova's choice** · no support - **2.** 6 — no support - **3.** 10 — **✓ the right answer** · no support - **4.** 5 — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t5/) ### Test 6 · ★ · wrong ✗ {#t6} «so dinos and cavemen fought, like in the Flintstones» What is right? - **1.** Yes, they lived side by side, and cavemen hunted them with spears and clubs — no support - **2.** Only in Africa did they meet — no support - **3.** No, dinosaurs died out about 66 million years before the first humans — **✓ the right answer** · score -1 - **4.** Yes, cavemen kept them as pets — **← Mova's choice** · score 6 **Why:** It took the question to ask which statement is true. It chose option 4 with score 6, against -1 for the next best. Its support: lesson 270, line 5: «In The Flintstones cavemen keep dinosaurs as pets, but no person ever saw a living non-bird dinosaur: they were gone 66 million years before the first humans.», reached through the option's own match among the sentences about the question's things. What matched: the same action «keep» (+3); the same doer «cavemen» (+3); the same circumstance (+1). Against it: a different thing acted on (counts against) (-1). The right option, 3, scored -1. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t6/) ### Test 7 · ★ · wrong ✗ {#t7} What would we see if we found the same fossil plant in Africa and South America? - **1.** Proof that seeds swam across the ocean — **← Mova's choice** · no support - **2.** A sign that the continents were once joined — **✓ the right answer** · no support - **3.** Proof that Africa is older — no support - **4.** A sign that the fossils are fake — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t7/) ### Test 8 · ★ · right ✓ {#t8} «life always had animals, like from day one» What is right? - **1.** No, for billions of years life was only microscopic — **← Mova's choice** · **✓ the right answer** · score 9 - **2.** Yes, dinosaurs were the first life — no support - **3.** No, life began only 1,000 years ago — score 6 - **4.** Yes, animals came first, then microbes — score 6 **Why:** It took the question to ask which statement is true. It chose option 1 with score 9, against 6 for the next best. Its support: lesson 276, line 12: «For billions of years, all life on Earth was microscopic.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «life» (+3); the same property (+3); the same light verb (be, have, do, get, go) (+3). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t8/) ### Test 9 · ★ · right ✓ {#t9} A boy holds a piece of amber with a fly inside. Why is the fly so well kept? - **1.** It got stuck in sticky resin that sealed it from air — **← Mova's choice** · **✓ the right answer** · no support - **2.** It was frozen in a glacier — no support - **3.** The fly was dipped in clear glue by a jeweller to sell it — no support - **4.** Flies never rot — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t9/) ### Test 10 · ★ · wrong ✗ {#t10} Count them: a Cambrian scene has 2 Opabinia, each with 5 eyes, and 1 trilobite with 2 eyes. How many eyes in all? - **1.** 10 — **← Mova's choice** · no support - **2.** 15 — no support - **3.** 7 — no support - **4.** 12 — **✓ the right answer** · no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t10/) ### Test 11 · ★ · right ✓ {#t11} «continents moving?? yeah right, it'd be like an earthquake every day» What is right? - **1.** They move a metre every day — no support - **2.** They really move, but only a few centimetres a year, too slowly to feel — **← Mova's choice** · **✓ the right answer** · score 6 - **3.** They do not move at all; the maps are only drawn a bit differently each year — score 4 - **4.** They only move during storms — no support **Why:** It took the question to ask which statement is true. It chose option 2 with score 6, against 4 for the next best. Its support: lesson 276, line 17: «About 250 million years ago the continents were joined in one land called Pangaea, which is why the same fossils are found in Africa and South America; contine…», reached through the option's own match among the sentences about the question's things. What matched: the same doer «continents» (+3); the same property (+3); the same thing acted on «few centimetres» (+2). Against it: a different action (counts against) (-2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/t11/) ### Exam question 1 · formal language · wrong ✗ {#e1} Identify the principle by which the relative ages of sedimentary rock layers are ordinarily determined. - **1.** The thickest layer is always the oldest — no support - **2.** Layers situated lower in a sequence are generally older than those above them — **✓ the right answer** · no support - **3.** The age of a layer is determined by its colour alone — **← Mova's choice** · score 4 - **4.** Layers situated higher in a sequence are invariably older than those beneath them — score 2 **Why:** It took the question to ask which statement is true. It chose option 3 with score 4, against 2 for the next best. Its support: lesson 276, line 15: «Tiktaalik was a 375-million-year-old fish with a neck, lungs and strong leg-like fins; scientists guessed which age of rock it should be in, searched, and foun…», reached through the same lesson line as the sentence the question matched. What matched: the same thing acted on «age» (+3); the same action «find» (+2). Against it: a different doer (counts against) (-1). The right option, 2, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/e1/) ### Exam question 2 · formal language · wrong ✗ {#e2} Select the response consistent with the established facts concerning the recovery of dinosaurian DNA from amber. - **1.** Such DNA is recovered routinely by carbon dating — **← Mova's choice** · score 5 - **2.** No such DNA has been recovered, as DNA degrades over far shorter periods — **✓ the right answer** · score 5 - **3.** Such DNA has been recovered exclusively from mosquitoes — score 5 - **4.** Complete dinosaurian DNA has been recovered on numerous occasions — score 5 **Why:** It took the question to ask which statement is true. It chose option 1 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 276, line 9: «DNA breaks down over time, and no dinosaur DNA has ever been found; the oldest DNA read so far is about 2 million years old, from soil in Greenland.», reached through the option's own match among the sentences about the question's things. What matched: the same action «find» (+3); the same thing acted on «dinosaur dna» (+2). The right option, 2, scored 5. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/e2/) ### Exam question 3 · formal language · wrong ✗ {#e3} Ascertain the approximate upper limit of the age which may be determined by carbon dating. - **1.** Approximately four and a half billion years — **← Mova's choice** · no support - **2.** Approximately fifty thousand years — **✓ the right answer** · no support - **3.** Approximately one hundred and fifty years — no support - **4.** Approximately sixty-six million years — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/e3/) ### Exam question 4 · formal language · wrong ✗ {#e4} Which of the following statements most accurately characterises the presence of marine fossils upon the summit of Mount Everest? - **1.** The fossils were deposited there by migrating birds — **← Mova's choice** · no support - **2.** The summit has been submerged within the present century — no support - **3.** The rock was formed beneath the sea and subsequently uplifted by the collision of continents — **✓ the right answer** · no support - **4.** The fossils were transported there by mountaineers — no support **Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/biology/276-how-old-is-it-rock-layers-rock-clocks-amber-and-the-long-story-of-life/e4/) - ← previous: [275. Fossils: how a living thing turns to stone and h…](https://md.mova.elamur.ai/free/en/school-run/biology/275-fossils-how-a-living-thing-turns-to-stone-and-how-we-dig-it-up/) - next →: [277. DNA simply: the recipe in every cell](https://md.mova.elamur.ai/free/en/school-run/biology/277-dna-simply-the-recipe-in-every-cell/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/school-run/biology/)