I think many folks have a severe misunderstanding of the how common core is related to reading material presented to the students.
There is no "science-knowledge" common core material. In common core, science has been integrated entirely within language arts: basically learning the ability to take reading material covering a scientific topic and extract information from the reading material, not learn the subject.
The point is not to teach a12-year old the scientific topics of genetic counseling, meiosis, DNA, etc. It is not *knowledge* based learning, but learning the skills of how to extract facts from written material. At the 12-year old level, for scientific texts, common core wants students to be able to:
- quote accurately from a text
- identify 2 or more main ideas from a text and summarize how they are supported by details
- explain the relationship or interaction between 2 or more ideas in the text
- determine the meaning of common scientific words appropriate to grade level
- compare and contrast two texts on the same subject
- draw on multiple texts to find the answer to a question
- explain how the author uses certain evidence or reasoning to support a specific point
- be able to integrate information from multiple texts on the same topic in a writing or speaking exercise
Not surprisingly, these new "science" skills are difficult for students trained to study "topics" and "facts", or have advanced and/or extra-curricular knowledge of a topic from other sources (say a parent), but is a lazy reader or doesn't usually want to examine and/or integrate information from multiple sources (e.g., likes discovering facts from single-source resources like Wikipedia or other Encyclopedia-like authoritative-resource). The goal of common core is not to learn any specific scientific topics, but to teach students how to discover knowledge in a critical-learning way from multiple sources of information. Hopefully these will be useful skills regardless of the topic presented, but is a radical shift in the goal (and probably not well communicated or taught by teachers used to the old fact-based curriculum).
I suspect this is why far-left-leaning and far-right-leaning folks seem to be so dead-set against Common-Core. Training people to get information from multiple sources and identify what evidence they are using to support their point of view is tantamount to learning to think for themselves. You might see how this is really scary for political movements that depend on low-information voters who are expected to tow-the-line...
Don't fret if you child doesn't understand all the nuances of meiosis or DNA, or genetic counseling from reading the supplied texts. The point is for them to learn to be able to read the text and extract ideas, viewpoints, and the logical reasoning (or lack thereof) in the supplied texts. The facts and topics themselves in the reading material are just supposed to be relevant and timely, not canonical parts of a curriculum. Hopefully it will inspire them to do more learning on their own if the topics are interesting (which is why they are supposed to be relevant and timely).