Answer:
Conducting an experiment.
Fro the answer to the question above,
<span>Based on fossil evidence, eukaryotes evolved about <u>2.1 billion</u> years ago</span>.
<span>Approximately the first single-celled Eukaryotes appeared 2.1billion years</span>.
But the multicellular eukaryotes first appeared at 1.5 billion years ago.
I hope this helps
Enzymes are sometimes called biological catalysts
Answer:
More than 7000 chemicals are present in tobacco smoke.
Explanation:
In these 7000 chemicals, 250 are harmful to the human body such as carbonmonoxide, ammonia and hydrogen cyanide etc. There are some chemicals that are found in tobacco smoke which causes cancer disease in human. About 69 chemicals out of 250 are present in tobacco smoke that causes cancer disease. So its consumption is dangerous for health.
