How an author sharpens a key term across a text
Grade 11 Reading Worksheet - Building Confidence
Circle the best answer.
Read this first
What Biologists Mean by a Species (science article)
[1] In everyday speech, a species is simply a kind of living thing, so a robin, a red maple and a monarch butterfly each count as one. [2] Biologists use the same word, but over three centuries they have worked hard to say exactly what makes one kind different from another. [3] The meaning they settled on is narrower than the everyday one, and even that meaning has limits that biologists admit.
[4] In 1735 the Swedish naturalist Carl Linnaeus published a system that sorted plants and animals into groups by features that anyone could see, such as the parts of a flower or the shape of a bird's beak. [5] For Linnaeus and the many naturalists who followed him, a species was a group of living things that looked alike in these important features. [6] That definition worked well for specimens laid side by side in a museum drawer, but it ran into trouble in fields and forests.
[7] Some birds that look almost identical turn out to be separate species, such as the eastern and western meadowlarks, which are told apart most easily by their songs. [8] Other animals look very different and still belong to one species, as when the males and females of many ducks wear completely different feathers. [9] In 1942 the biologist Ernst Mayr proposed a sharper test: a species is a group of populations whose members can breed with one another and produce young that can also breed, and that do not breed with other groups. [10] By this test, horses and donkeys are separate species, because their offspring, the mule, is almost always unable to have young of its own. [11] Looks still matter as clues, but under Mayr's definition the deciding question is which animals can breed with which.
[12] Even this sharper meaning does not reach every living thing, because bacteria and many other organisms reproduce without mates at all. [13] It also cannot be tested on fossils, since no one can watch animals that lived millions of years ago choose their partners. [14] For these cases biologists still compare body shapes and, increasingly, the DNA inside cells, so the word now names one idea that is checked in several ways.
Tala marks how sentence 9 changes the term. How does sentence 9 change the meaning of species?
- It narrows it: a species is a group whose members can breed together and have young that breed.
- It gives one more example of the older meaning, like the meadowlarks of sentence 7.
- It widens it: species now covers any animals that are able to breed, horses and donkeys together.
- It narrows it: a species is a group of birds that can be told apart by their songs.
Jun looks for the first meaning that biologists, not everyday speakers, gave to species. Which sentence states it?
- Sentence 9, where a species is a group whose members can breed and have young that breed.
- Sentence 5, where a species is a group of living things that look alike in key features.
- Sentence 1, where a species is simply a kind of living thing, such as a robin.
- Sentence 2, where biologists are said to use the same word as other speakers.
Pia writes the last meaning-so-far note, for sentences 12 to 14. What does species mean by the end of the article?
- Any set of organisms that share DNA, so the breeding test has been set aside.
- The breeding test where it can be used, with shape and DNA checking the cases it cannot reach.
- A group that looks alike in body shape, since biologists still compare shapes.
- Simply a kind of living thing again, because the sharper test failed for bacteria.
Bo reaches the rung for sentence 12. How does sentence 12 change the meaning of species built so far?
- It gives another example of the breeding test, like the horses and donkeys of sentence 10.
- It widens the breeding test so that it now covers bacteria and other organisms without mates.
- It sets a limit: the breeding test cannot reach living things that reproduce without mates.
- It shows that the word species no longer has any exact meaning in biology.
What Makes a Test Fair (science article)
[1] When people call a game or a contest fair, they usually mean that the rules treat every player the same way and that no one has been given a secret advantage. [2] Scientists borrow this word when they speak of a fair test, but in a laboratory it takes on a narrower and more demanding meaning. [3] A single clear example shows how that meaning is built, one requirement at a time.
[4] Imagine a class that wants to know whether the height of a ramp changes how far a toy car rolls once it reaches the floor. [5] The factor the class changes on purpose, the height of the ramp, is called the independent variable, and the distance the car rolls is what the class measures. [6] A test is fair, in the scientist's first sense, when that one factor is changed and everything else is kept exactly the same from one run to the next. [7] If the class used a heavier car on the higher ramp, nobody could say whether the height or the weight had made the car roll farther.
[8] Keeping the other factors steady is not enough on its own, however, because a single run can be thrown off by a small bump or a crooked start. [9] For that reason, a fair test also repeats each height several times and compares the averages rather than trusting any one result. [10] It also measures the same way every time, from the same mark on the floor, so the numbers being compared mean the same thing.
[11] Careful testers also list every factor they held steady, so that another class could repeat the test and check the result. [12] Notice that none of these requirements makes the experiment fair to the toy car or to the students in the way a game is fair to its players. [13] In science, a test is fair when it is fair to the question being asked, so that a change in the result can be traced to the one factor that was changed. [14] That is a much stricter meaning than the everyday word suggests, and it is the one a good science report is expected to use.
Milo starts a ladder for the word fair. What does fair mean in its everyday sense, on the first rung?
- One factor is changed and everything else is kept the same from run to run in an experiment.
- The rules treat every player the same way, and no one gets a secret advantage.
- Honest results, which is the sense scientists keep all the way through.
- A game or a contest, the things that people usually call fair.
Zee writes the meaning-so-far note after sentence 7. What does a fair test mean at this point?
- A test in which the class uses the same toy car on every ramp it tries.
- A test that changes one factor, repeats each run and compares the averages.
- A test in which every student in the class is treated alike and gets a turn.
- A test in which one factor is changed on purpose and every other factor stays the same.
Kira reaches the rung for sentence 9. How does sentence 9 change what counts as a fair test?
- It gives an example of the first requirement, keeping one factor steady.
- It adds a requirement: another class must repeat the whole test to check it.
- It replaces the first requirement, so the other factors no longer need to stay the same.
- It adds a requirement: each height is run several times and the averages are compared.
Ren reads sentence 2, where scientists borrow the word fair. What happens to the word's meaning when they borrow it?
- It keeps its everyday meaning, so a fair test treats each student alike.
- It now covers each kind of test, in games and in laboratories alike.
- It takes on a narrower and more demanding meaning than it has in games.
- It becomes looser, so that more kinds of tests count as fair in a laboratory.
Esme writes the last meaning-so-far note, for sentences 12 to 14. What does a fair test mean by the end?
- A test that is fair to the students and the toy car, like a game with even rules.
- A test in which one factor changes and the other factors stay the same.
- A test that repeats each height several times and then compares the averages.
- A test fair to the question, so a change in the result traces to the one factor changed.
Noah reaches the rung for sentence 12. How does sentence 12 change the meaning of fair test?
- It shows that the scientific meaning is unfair, because it ignores the students.
- It joins the two meanings, so a fair test is fair to students and to the question.
- It sets a limit: the requirements do not make the test fair to players, as a game is.
- It gives another example of a requirement, like measuring from the same mark.
