Answer:
The answer is A
By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
Hypertrophy is the process that occurs when fat cells swell and enlarge. Hope this helps!
A first-hand source such as an experiment is called a primary source.
A primary source is where you can share new information or report on what you have discovered. Some primary sources are research data, interviews, audio recordings, and autobiographies.
A secondary source is where you describe and discuss about the primary sources. They are used to collect and gather primary source information. Some secondary sources are textbooks, review articles, and scholarly books.
A tertiary source is a source about summaries. A tertiary source can be used to look up information or get an overview about what it is you are wanting to know. Some tertiary sources are dictionaries, handbooks, encyclopedias, Wikipedia, and guidebooks.
