**Optional.** Scientific ideas about how life began
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
Table, The Miller–Urey experiment (NASA), with columns Part, What it stood for or gave
Flask of water, an early ocean; Methane, ammonia, hydrogen and water vapor, an early atmosphere, as Urey proposed; Electric sparks, lightning; Result in 1953, 5 amino acids identified; Re-analysis in 2008 of a sibling experiment, 22 amino acids.
A classmate says the Miller–Urey experiment created life in a flask. Which reply fits NASA, by Esme's reading?
- Correct; it made complete cells that held both DNA and RNA
- No; the flask stayed exactly as it started, with no new molecules
- No; it made amino acids, building blocks of proteins, not living cells
- Correct; bacteria grew in the flask within a few days after the sparks were sent
RNA, DNA and a protein, with the jobs each can do. A student says the RNA world idea means DNA came first. Which reply fits NASA, by Kira's reading?
- Correct; DNA came first, and then RNA was copied out from it later on
- Correct; proteins came first, then DNA, then RNA
- No; it proposes RNA first, later replaced by DNA and proteins
- No; it proposes that stromatolites came first
Table, Early Earth timeline (NASA), with columns Event, When
Earth forms, about 4.5 billion years ago; Possible earliest signs of life, about 4 billion years ago; Pilbara stromatolites, Australia, about 3.5 billion years ago; Miller–Urey paper in Science, May 15, 1953.
Using the timeline, how much older is Earth than the possible earliest signs of life, by Luz's math?
- About 50 million years
- About 0.5 billion years (500 million)
- About 8.5 billion years
- About 4.5 billion years, since life began with Earth
Model scale: Earth's 4.5-billion-year history is one 24-hour day starting at midnight. About when would the 3.5-billion-year-old stromatolites appear, by Milo's math?
- About 6:40 p.m.
- About 5:20 a.m.
- About 1:00 a.m.
- About 3:30 a.m.
Model data: a stromatolite grew 0.4 mm a year for 2,500 years. How tall did it grow, by Noah's math?
- About 100 mm
- About 1,000 mm (1 m)
- About 6,250 mm
- About 2,500.4 mm
Which evidence best supports that life existed 3.5 billion years ago, by Pia's reading (NASA)?
- RNA strings that grew into full genes at a lab bench in 2016, on their own
- Living bacteria found in the air of the giant planets
- Amino acids that formed in a flask of living bacteria in 1953
- Pilbara stromatolites, built by microbial mats about 3.5 billion years ago
Table, The Miller–Urey experiment (NASA), with columns Part, What it stood for or gave
Flask of water, an early ocean; Methane, ammonia, hydrogen and water vapor, an early atmosphere, as Urey proposed; Electric sparks, lightning; Result in 1953, 5 amino acids identified; Re-analysis in 2008 of a sibling experiment, 22 amino acids.
Which result best supports that life's building blocks can form from simple chemicals, by Ren's reading (NASA)?
- Living cells came out of the 1953 flask
- DNA forms first in a cell, with no proteins needed
- Miller–Urey sparks made amino acids from water and simple gases
- Stromatolites formed from sea-floor sand with no microbes involved
A pond, a tide pool, a hot spring and a seafloor vent chimney. Two hypotheses: life began in a warm pond, or at a deep-sea vent. Which kind of evidence could help test them, by Tala's reading?
- A vote on which idea sounds nicer to most people
- Counting how many stars can be seen in the sky
- Lab tests of which setting forms and protects molecules like RNA
- Assuming that the older idea must be the right one
Table, The Miller–Urey experiment (NASA), with columns Part, What it stood for or gave
Flask of water, an early ocean; Methane, ammonia, hydrogen and water vapor, an early atmosphere, as Urey proposed; Electric sparks, lightning; Result in 1953, 5 amino acids identified; Re-analysis in 2008 of a sibling experiment, 22 amino acids.
Which summary of the Miller–Urey experiment fits NASA, by Ari's reading?
- Sunlight on rocks made DNA and settled how life began
- Sparks in water and simple gases made amino acids, though early air may have differed
- Sparks in oxygen-rich air made living bacteria in about a week, settling the question
- Sparks in water turned simple gases into stromatolites
RNA, DNA and a protein, with the jobs each can do. Which summary of the RNA world idea fits NASA, by Bo's reading?
- DNA came first and later turned into RNA and proteins, which then took over its jobs
- RNA was found fully formed in a 1953 flask
- RNA may have stored data and sped reactions before DNA and proteins took over
- RNA cannot store data, so proteins came first