GRADE 5 READING TEST AUTHOR'S PURPOSE with Answer Key

 Reading Comprehension Assessment Series 

GRADE 5 AUTHOR'S PURPOSE

Ocean Acidification: Chemistry, Crisis & Collective Will

 Understanding Author's Purpose: A Parent Guide

GRADE 8 Reading Test AUTHOR'S PURPOSE With Answer Key

GRADE 7 Reading Test AUTHOR'S PURPOSE with Answer Key
GRADE 6 READING TEST: AUTHOR'S PURPOSE with Answer Key
GRADE 5 READING TEST AUTHOR'S PURPOSE with Answer Key
GRADE 4 READING TEST AUTHOR'S PURPOSE with Answer Key
GRADE 3 READING TEST: AUTHOR'S PURPOSE

Webb's Depth of Knowledge  ·  Hess's Cognitive Rigor Matrix

Tier 2 & Tier 3 Academic Vocabulary  ·  Frustration-Level Text

 

Student Name: _________________________________    Date: ____________

Teacher: _________________________________    Period/Class: ____________

 

DIRECTIONS

Read the passage carefully. Annotate for author's purpose, word choice, and rhetorical strategies. Answer every question using complete sentences and direct textual evidence.

 

PASSAGE: THE HIDDEN COST OF AN OBLIGING OCEAN

 

The ocean absorbs approximately 25 percent of all carbon dioxide emitted by human activity each year—a fact that has led many policymakers and scientists to characterize the ocean as Earth's most vital carbon sink. Yet this characterization, while factually accurate in isolation, dangerously obscures the catastrophic consequences of that absorption process. As the ocean takes in carbon dioxide, it undergoes a chemical transformation: carbon dioxide dissolves in seawater to form carbonic acid, which then dissociates into hydrogen ions and bicarbonate. The resulting increase in hydrogen ion concentration is what scientists call ocean acidification.

The pH scale, which measures the acidity or alkalinity of a substance, ranges from 0 (most acidic) to 14 (most alkaline), with 7 representing a neutral state. The ocean's average surface pH has decreased from approximately 8.2 to 8.1 since the Industrial Revolution—a change that appears numerically negligible. However, because the pH scale is logarithmic, this 0.1-unit decrease actually represents a 26 percent increase in acidity. This seemingly subtle shift has profound and measurable consequences for marine ecosystems.

Calcifying organisms—marine animals that construct shells or skeletal structures from calcium carbonate—are disproportionately vulnerable to ocean acidification. Corals, oysters, mussels, sea urchins, and pteropods (free-swimming sea snails) all rely on the availability of carbonate ions to build and maintain their structures. As seawater becomes more acidic, carbonate ions become less available, and the shells of these organisms literally dissolve. Coral reefs, which support approximately 25 percent of all ocean biodiversity despite covering less than 1 percent of the ocean floor, face existential threat from this process.

Proponents of carbon capture technology argue that engineered solutions—such as iron fertilization of the ocean or direct air capture of carbon dioxide—offer a viable path to stabilizing ocean pH without requiring the dramatic reductions in fossil fuel consumption that many governments find politically untenable. Critics, however, contend that these technologies are unproven at scale, potentially introduce new ecological risks, and represent a moral hazard by providing industries with justification to continue emitting carbon rather than fundamentally restructuring their practices.

What is ultimately at stake is not merely an ecological question but an epistemological one: how do human beings weigh short-term economic interests against long-term ecological consequences when the full magnitude of those consequences may not manifest for decades? The scientific consensus is unambiguous—ocean acidification is accelerating, and its effects are irreversible on any human timescale. What remains contested is not the science but the question of collective will.

 

SECTION A — MULTIPLE-CHOICE QUESTIONS  (4 pts each)

DOK Levels 2–4  |  Hess CRM Cells B-2 through D-4

 

1. The author's primary purpose in this passage is to —

DOK 2  |  CRM Cell B-2

A)  argue that the ocean should no longer be considered a carbon sink because it is too harmful

B)  entertain readers with dramatic descriptions of dying coral reefs

C)  inform readers about the chemistry and ecological consequences of ocean acidification while also exposing the complexity of proposed solutions

D)  persuade readers to oppose fossil fuel companies by revealing scientific data they have concealed

2. In paragraph one, the author states that calling the ocean a carbon sink is "factually accurate in isolation" but "dangerously obscures" important consequences. What does this phrasing reveal about the author's rhetorical strategy?

DOK 3  |  CRM Cell C-3

A)  The author is uncertain whether the ocean actually absorbs carbon dioxide

B)  The author deliberately acknowledges a scientific truth before immediately complicating it, establishing credibility while simultaneously creating an argumentative tension that drives the rest of the passage

C)  The author is trying to confuse readers so they cannot form an opinion about climate change

D)  The author agrees that characterizing the ocean as a carbon sink is completely accurate and unproblematic

3. The author explains the logarithmic nature of the pH scale in paragraph two. Why is this explanatory move critical to the author's purpose?

DOK 3  |  CRM Cell C-3

A)  It provides unnecessary scientific detail that distracts from the main argument

B)  Without this explanation, readers would likely underestimate the severity of a 0.1-unit pH change, which would undermine the author's implicit argument that ocean acidification is a serious and urgent threat

C)  It demonstrates that the author is a professional chemist with expertise in marine science

D)  It persuades readers that the pH scale is too complicated for non-scientists to understand

4. The final paragraph introduces an "epistemological" question about how humans weigh short-term and long-term consequences. How does this shift from scientific to philosophical framing affect the author's overall purpose?

DOK 4  |  CRM Cell D-4

A)  It weakens the passage by moving away from concrete scientific evidence toward abstract speculation

B)  It elevates the passage from a scientific report to a meditation on human decision-making, expanding the author's purpose to include a critique of how societies reason about risk and responsibility—and implicitly challenging readers to examine their own assumptions

C)  It signals that the author has run out of scientific evidence and must resort to philosophy to fill space

D)  It suggests that the author believes the scientific data on ocean acidification is unreliable

5. A skeptical reader argues: "The author presents both sides of the carbon capture debate, so this passage is completely objective with no discernible opinion." Which evidence BEST refutes this claim?

DOK 4  |  CRM Cell D-4

A)  The author mentions coral reefs, which is objective scientific information

B)  The author's language throughout—"dangerously obscures," "existential threat," "moral hazard," "collective will"—reveals a perspective aligned with urgency about climate change, suggesting the appearance of objectivity masks an implicit argumentative purpose

C)  The author defines technical terms like pH and logarithmic scale, which are neutral by definition

D)  The author cites specific statistics about coral reefs and ocean pH, which cannot be disputed

 

SECTION B — SHORT ANSWER  (10 pts each)

DOK Levels 3–4  |  Complete sentences required. Cite line-level evidence.

 

6. The author describes the "moral hazard" of carbon capture technology (paragraph 4). Define moral hazard in your own words using context clues, then analyze why the author introduces this concept at this specific point in the passage rather than earlier or later. What does its placement reveal about the author's purpose? (DOK 3 | CRM C-3)

Your response:

 

 

 

 

7. The author concludes by stating: "What remains contested is not the science but the question of collective will." Analyze this sentence as a rhetorical choice. What assumption does the author make about the reader in writing this sentence? Does this assumption shift the passage's purpose from informative to persuasive? Defend your position. (DOK 4 | CRM D-4)

Your response:

 

 

 

 

SECTION C — EXTENDED RESPONSE  (20 pts)

DOK Level 4  |  Hess CRM Cell D-4  |  Minimum 12 sentences. Formal academic register required.

 

8. Author's Purpose Analysis Essay: This passage operates simultaneously as scientific exposition, policy analysis, and philosophical inquiry. In a well-organized extended response: (1) identify and distinguish the author's primary and secondary purposes; (2) analyze how the author's progression from chemistry → ecology → policy debate → philosophy reflects a deliberate rhetorical architecture; (3) evaluate the effectiveness of the author's diction choices—particularly "dangerously obscures," "existential threat," and "epistemological"—in advancing each purpose; and (4) argue whether the author succeeds in maintaining intellectual balance or whether a discernible perspective ultimately dominates the passage. Support every claim with specific textual evidence.

 

 

 

 

 

 

 

 

 

 

 

 

 

SECTION D — VOCABULARY IN CONTEXT  (4 pts each)

 

9. The word "dissociates" (paragraph 1) in the context of the chemical reaction described most nearly means —

A)  combines permanently with another compound to form a stable new molecule

B)  breaks apart into separate components or ions

C)  evaporates and escapes into the atmosphere above the water

D)  becomes neutral and no longer reacts chemically with other substances

 

10. The word "untenable" (paragraph 4) describes the position of governments regarding fossil fuel reductions. In this context, "untenable" most nearly means —

A)  widely accepted and politically popular among voters

B)  technologically impossible to implement with current engineering

C)  not capable of being defended, maintained, or sustained—politically indefensible

D)  economically profitable in the short term for fossil fuel corporations

 

ASSESSMENT SCORING GUIDE

Section	Points Possible	Points Earned	DOK Level	CRM Cell
MC Questions (x5)	20	___	2–4	C-3 / D-4
Short Answer (x2)	20	___	3–4	C-3 / D-4
Extended Response	20	___	4	D-4
Vocabulary	20	___	2–3	B-2
TOTAL	80	___	—	—

Author's Purpose Assessment Series — ANSWER KEY & SCORING GUIDE

Grades 3–8  |  For Teacher Use Only

 

 

Grade 3 — Author's Purpose Assessment

 

Multiple-Choice Answers:

Question 1: C

Question 2: B

Question 3: B

Question 4: C

Question 5: B

Vocabulary Answers (Questions 9–10):

Question 9: B

Question 10: B

Short-Answer & Extended Response Scoring:

Score using the DOK/CRM rubric below. Award full credit for responses that: (1) provide a precise, text-grounded claim; (2) cite specific evidence; (3) demonstrate analytical rather than merely retelling reasoning; and (4) employ grade-appropriate academic register.

 

Grade 4 — Author's Purpose Assessment

 

Multiple-Choice Answers:

Question 1: B

Question 2: B

Question 3: B

Question 4: B

Question 5: B

Vocabulary Answers (Questions 9–10):

Question 9: B

Question 10: C

Short-Answer & Extended Response Scoring:

Score using the DOK/CRM rubric below. Award full credit for responses that: (1) provide a precise, text-grounded claim; (2) cite specific evidence; (3) demonstrate analytical rather than merely retelling reasoning; and (4) employ grade-appropriate academic register.

 

Grade 5 — Author's Purpose Assessment

 

Multiple-Choice Answers:

Question 1: C

Question 2: B

Question 3: B

Question 4: B

Question 5: B

Vocabulary Answers (Questions 9–10):

Question 9: B

Question 10: C

Short-Answer & Extended Response Scoring:

Score using the DOK/CRM rubric below. Award full credit for responses that: (1) provide a precise, text-grounded claim; (2) cite specific evidence; (3) demonstrate analytical rather than merely retelling reasoning; and (4) employ grade-appropriate academic register.

 

Grade 6 — Author's Purpose Assessment

 

Multiple-Choice Answers:

Question 1: C

Question 2: B

Question 3: B

Question 4: B

Question 5: B

Vocabulary Answers (Questions 9–10):

Question 9: B

Question 10: B

Short-Answer & Extended Response Scoring:

Score using the DOK/CRM rubric below. Award full credit for responses that: (1) provide a precise, text-grounded claim; (2) cite specific evidence; (3) demonstrate analytical rather than merely retelling reasoning; and (4) employ grade-appropriate academic register.

 

Grade 7 — Author's Purpose Assessment

 

Multiple-Choice Answers:

Question 1: B

Question 2: B

Question 3: B

Question 4: B

Question 5: B

Vocabulary Answers (Questions 9–10):

Question 9: B

Question 10: C

Short-Answer & Extended Response Scoring:

Score using the DOK/CRM rubric below. Award full credit for responses that: (1) provide a precise, text-grounded claim; (2) cite specific evidence; (3) demonstrate analytical rather than merely retelling reasoning; and (4) employ grade-appropriate academic register.

 

Grade 8 — Author's Purpose Assessment

 

Multiple-Choice Answers:

Question 1: C

Question 2: B

Question 3: B

Question 4: B

Question 5: B

Vocabulary Answers (Questions 9–10):

Question 9: C

Question 10: B

Short-Answer & Extended Response Scoring:

Score using the DOK/CRM rubric below. Award full credit for responses that: (1) provide a precise, text-grounded claim; (2) cite specific evidence; (3) demonstrate analytical rather than merely retelling reasoning; and (4) employ grade-appropriate academic register.

 

 

DOK / CRM Rubric for Open-Response Items

 

Score	DOK Level	Evidence	Analysis	Vocabulary & Register
18–20	4 — Extended Thinking	Multiple, specific, precise citations	Insight beyond restatement; evaluates, synthesizes	Tier 3 vocabulary; formal academic register throughout
14–17	3 — Strategic Thinking	Specific citations; mostly accurate	Analytical; explains rather than retells	Tier 2 vocabulary; generally formal
9–13	2 — Skills & Concepts	General or partial citations	Some analysis; relies partly on summary	Basic academic vocabulary
0–8	1 — Recall	No citations or inaccurate	Retelling without analysis	Informal or imprecise language