Carbon monoxide has a density that is about 97% that of air under normal room temperature. So, to answer the question, no, it is lighter than air. You would think, then, that it would rise. In real-world conditions, there are a lot of forces that cause the CO to mix rather completely into the air.
Growth Hormones. Growth Hormones are responsible for the development function of the entire body. Growth Hormones are peptide hormones which encourages growth and cell regeneration in both humans and animals.
Plant hormone. Lack of the plant hormone auxin can cause abnormal growth (right) Plant hormones (also known as phytohormones) are chemicals that regulate plant growth. In the United Kingdom, these are termed 'plant growth substances'. Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations.