I use this document with my first graders when we dissect flowers. I love that it saves us paper by printing 2/page -- it's the perfect size for fitting in our science notebooks, which are composition books.
Prior to class, I buy flowers at the local nursery, but you could have your students go outside and pick them on a nature walk.
I give each student 4 pieces of tape. Students must "dissect" their flower and tape the parts in the correct circle before answering the question at the bottom of the page. It's a fun day in science class!