Space Food Lesson
Lesson Navigation
Step 6: Methods Key Points
Progress: checking...
- Astronauts grew three crops of red romaine lettuce in consecutive years.
- Crops were grown on Earth at the same time and under the same conditions. They controlled for humidity, carbon dioxide, and temperature.
- Samples of leaves and roots were tested for nutrient levels. They were also tested for the foodborne pathogens E. coli and Salmonella.
- Researchers collected other bacteria and fungi from the leaves of the lettuce and grew them on petri dishes. Then they isolated DNA from the different colonies and identified them using a database. They also directly sampled the lettuce for any bacterial or fungal DNA.
and go through it step by step.
, but phone 
is an option too.
. You might have to use headphones. 
– they’ll help with the final quiz.
of the final screen and share it with your teacher.
incomplete.