Final answer:
The cognitive working system in question is language acquisition and literacy skills development, particularly focused on understanding word structures through prefixes, suffixes, and roots, enhancing both vocabulary and reading comprehension.
Step-by-step explanation:
During a guided reading activity of an informational text which emphasizes understanding word structures through the use of prefixes, suffixes, and roots, the cognitive working system involved is language acquisition and literacy skills development. This activity targets students' ability to decode and understand complex words by breaking them down into their constituent parts. This process enhances their vocabulary as well as reading comprehension skills, as they become more adept at interpreting the meaning of new terms and expressions within various texts.
For instance, learning about prefixes such as 'un-' (meaning 'not') or 'pre-' (meaning 'before') allows students to predict and understand the meanings of new words they encounter. As they engage in this aspect of language learning, students develop critical thinking and analytical skills necessary for success in reading and writing across all subjects.
Ultimately, through the study of word structure within reading activities, students can substantially improve their comprehension and interpretation of informational texts by being better equipped to understand the nuances of the language and literary devices used within.