1. Name:________________________________________Date:______________________Period:_________
Pre-test: Understanding Cells
1. The “basic units of life” are called __________________.
2. Two characteristics of living things are that they can ________ and ________________ .
3. The creatures seen here are called ___________________ because they have only one cell.
4. Bigger, more complicated creatures will have many more _________ than simpler ones.
5. Because they are highly organized in the way they are put together, living things are often
called _________________.
6. Similar kinds of cells usually form layers called __________________.
7. In multicellular organisms, cells have become _______________ to perform certain tasks.
8. The organ system used to pump blood is called the ________________ system.
9. The organ system for breathing is called the ___________________ system.
10. The brain is the main organ of the _________________ system.
11. Sugar is one of the main sources of __________ for cells.
12. The organelles called ______________ are also known as the powerhouses of the cell.
13. Tens of thousands of tiny “protein factories” called____________ are found on the surface of
much of the cell’s endoplasmic reticulum.
14.The organelles called ________________ are made in the nucleus in a special area called the
nucleolus.
15. Much of the material in the nucleus is used for storing_____________.
16. The language used by cells is known as the________________.
17. Chromosomes contain a long, twisted, thread–like, chemical called ________.
18. Chromosomes are not always visible in cells. They can be seen only when cells are getting
ready to ____________.
19. The cell’s language uses a chemical alphabet that is only _________ letters long.
20. Each set of protein plans is called a __________.
21. Before cells divide, the nucleus has to reproduce. This process is called __________.
22. DNA replication takes place during the first stage of nuclear reproduction called
_________________.
23. Sex cells have only _______ the number of chromosomes of body cells.
24. Fibers called ___________ ____________ form around the centrioles of animal cells during
the reproduction of the nucleus.
25. The process in which male and female sex cells join together is called ________________.