Nature · Level 4 · 148 words

The Strength of Spider Silk

Original passage © Team AM, written for Hone Literacy.

For its weight, spider silk is one of the strongest materials known. A strand far thinner than a human hair can stretch without snapping and absorb the impact of a flying insect many times the spider's size. Engineers admire silk because it combines two qualities that usually oppose each other: it is both strong and stretchy. Steel is strong but brittle, while rubber stretches but tears easily. Silk manages both, which is why a web can catch prey without shattering. A single spider can produce several kinds of silk from different glands, each tuned for a task. One sort forms the sturdy frame of the web, another the sticky spiral that traps insects, and yet another wraps eggs in a protective case. Scientists have long hoped to manufacture silk in factories for uses from medical stitches to lightweight armor, but reproducing the spider's recipe has proven stubbornly hard.

Comprehension questions

1. Why do engineers find spider silk especially impressive?

  • A It is heavier than steel
  • B It is both strong and stretchy, qualities that usually oppose each other
  • C It dissolves quickly in water
  • D It glows in the dark
Show answer

B. It is both strong and stretchy, qualities that usually oppose each other
The text says silk combines strength and stretchiness, two qualities that 'usually oppose each other.'

2. According to the passage, what is one kind of silk used for?

  • A Building the web's frame
  • B Digesting food
  • C Helping the spider see
  • D Producing venom
Show answer

A. Building the web's frame
The text says one sort of silk 'forms the sturdy frame of the web.'

3. In this passage, 'brittle' most nearly means

  • A easily stretched
  • B likely to snap or break
  • C very soft
  • D extremely heavy
Show answer

B. likely to snap or break
Steel is called 'strong but brittle,' contrasted with stretchy, so brittle means likely to break.

Source: Written for Hone Literacy. Original passage © Team AM, written for Hone Literacy.