种子 (zhǒngzi) means "seed" and refers to the reproductive unit of a plant. It is used in botanical, agricultural, and everyday contexts, and can also be used metaphorically to mean the "seed" or origin of something.
春天是播种子的最佳时节。
chūntiān shì bō zhǒngzi de zuìjiā shíjié.
Spring is the best time to sow seeds.
这些种子大概一周后就会发芽。
zhèxiē zhǒngzi dàgài yī zhōu hòu jiù huì fāyá.
These seeds will probably sprout in about a week.
奶奶把花的种子种在了阳台上。
nǎinai bǎ huā de zhǒngzi zhòng zài le yángtái shàng.
Grandma planted flower seeds on the balcony.