Cell replication in single-celled organisms involves the acquisition of matter from their environment, which is essential for growth and reproduction. These organisms obtain necessary materials through various means, such as consuming other organisms or absorbing nutrients from their surroundings. For instance, protists may consume other protists, while plants like moss extract nutrients from trees. Environmental factors can influence how organisms gather materials, leading to adaptations like the Venus flytrap's ability to catch insects for nitrogen. When bacteria replicate, they utilize nutrients from their environment, often provided in laboratory settings through substances like agar gel rich in sugars. This breakdown of sugars allows bacteria to form RNA and other structures necessary for replication. The discussion also touches on the broader concept of how larger organisms, such as trees, derive their mass from carbon dioxide and water, which are transformed into sugars through metabolic processes. Overall, all life forms have metabolic pathways that convert environmental resources into the matter needed for growth and reproduction.