13. A. Cells

14. C. Both A and B

15. C. Plant

→Not sure of answers pero pretty sure I'm right maliban sa 15 :))

Answer:

13. A. Cells

14. A

15. A

Explanation:

13. All living things, large or small, plant or animal, are made up of cells. Most living things are made up of one cell and they are called unicellular organisms. Many other living things are made up of a large number of cells that form a larger plant or animal. These living things are known as multicellular organisms.

14. Both plant and animal cells are eukaryotic, so they contain membrane-bound organelles like the nucleus and mitochondria. However, plant cells and animal cells do not look exactly the same or have all of the same organelles, since they each have different needs.

15. Some scientists estimate that 'life' began on our planet as early as four billion years ago. And the first living things were simple, single-celled, micro-organisms called prokaryotes (they lacked a cell membrane and a cell nucleus).