Mutorials is a

science trainer.

Practice thousands of science problems from honors curriculum to national competition level—all with explanations.

Get started
image/svg+xml

Wide coverage

Four core subjects with 60 distinct units.

Physics

24 units

Chemistry

21 units

Biology

9 units

Earth & Space

7 units

4016

original questions

419

unique tags

39665

total solves

Daily Question

Try today's daily question!

July 19, 2024

The heterocyst-forming cyanobacterium Richelia intracellularis has a symbiotic relationship with the species Hemiaulus hauckii, where the former fixes atmospheric nitrogen within the heterocyst and provides the latter with the fixed nitrogen. What type of marine microorganism is H. hauckii?

Your answer is correct!
Your answer is incorrect.

Go to the daily question page to view the answer explanation!

Learn and grow with the Mutorials community.

Connect with fellow learners, discuss science topics, and stay updated on challenges in the Mutorials Discord server.

Join the Discord
Rank Username Level Experience
1 shiv779 55 3,121,446
2 thefalloutof76.dev 49 2,475,974
3 N.J. 49 2,413,108
4 rithvikd 46 2,113,906
5 tacosmoothie 44 1,976,792
6 karzinisierung 44 1,956,859
7 zjan7 43 1,877,250
8 dannyridel 43 1,840,963
9 apples 42 1,760,034
10 atomicweight 37 1,341,717

NEW!

USABO Training

Train for the USA Biology Olympiad, the premiere high-school biology competition in the United States.

Let's do some bio

Get started today.