Photosynthesis and cellular respiration are cells occur in cells.
a)chemical reactions.
b)physical reactions

A) chemical reactions.

Explanation:

"Photosynthesis is the process through which plants convert light energy into chemical energy. Here is the chemical reaction involved: As we can see, water and carbon dioxide combine to form glucose and oxygen. Since new chemical species are formed, photosynthesis is clearly a chemical change. "

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

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements