Which of these work together in a feedback loop?

A. Thyroid and parathyroid gland

B. Hypothalamus and pituitary gland

C. Adrenal and pineal gland

D. Ovaries and salivary gland

thinking it would be physical characteristics

answer: angiosperms

dicots

angiosperms are highly evolved plants, they produce seeds which are enclosed within in a carple. these are the largest group of plants on earth. they include trees, shrubs, herbs and small flowering plants. angiosperms exhibit a flowering stage in their life cycle. the flower serves the function of reproduction and fruit formation in majority of angiosperms. dicot is the term used to describe flowering plants that have two seed leaves. dicots are plants which develop seeds which split into two parts called cotyledons. each cotyledon contains one embryo.

here, a small purple flower development indicates that the plant belongs to angiosperms and having two embryonic leaves indicates it belongs to dicots.  

which fault and or fold did you find most difficult to diagram