催生素

• 亻(person; human)RADICAL
• 崔(steep mountain; climb)PHONETIC

People urge each other to hurry up like climbing a steep mountain, where you must move your feet quickly to keep pace.

• 生(life; sprouting)ASSOCIATIVE

The character depicts a sprout pushing up through the soil, symbolizing life and growth.

• 糸(silk thread; filament)RADICAL
• 龶(coarse undyed thread bundle; top part of thread)ASSOCIATIVE

Raw silk that hasn't been dyed suggests the meaning of pure, simple, and basic.