Answer:
1. The three components of the plasma membrane are lipids (phospholipids and cholesterol), proteins, and carbohydrates.
2. The nucleus is the organelle that contains most of the cell's genetic information.
3. Mitochondria are found in large numbers in active cells, such as muscle cells, because they produce chemical energy in the form of ATP.
4. Chloroplasts are organelles found in plant and algae cells but not animal cells.
5. Phagocytes use lysosomes to digest pathogens.
6. Ribosomes are the organelles that carry out protein synthesis.
7. The rough endoplasmic reticulum (RER) is involved in the synthesis, folding, and modification of proteins.
8. The smooth endoplasmic reticulum (SER) is involved in the synthesis of lipids, steroid hormones, detoxification of harmful metabolic byproducts, and storage and metabolism of calcium ions within the cell.
9. The Golgi body is responsible for transporting, modifying, and packaging proteins and lipids into vesicles for delivery to targeted destinations.
10. The function of a cell wall in plant cells is to provide mechanical protection and a chemically buffered environment, provide a porous medium for the circulation and distribution of water, minerals, and other small nutrient molecules, provide rigid building blocks from which stable structures of higher order can be produced, and provide a storage site of regulatory molecules that sense the presence of pathogenic microbes and control the development of tissues.
11. A group of the same type of cell working together is called a tissue.
12. An organ is a group of tissues that work together to perform a specific function or set of functions within an organism.
13. Animal and plant cells are eukaryotic cells.
14. Prokaryotic cells do not have membrane-bound organelles such as a nucleus, mitochondria, or chloroplasts.
15. The DNA in a prokaryote is usually circular and is found in the cytoplasm in a region called the nucleoid.
16. A virus is made up of a nucleic acid core (either DNA or RNA), a protein coat called a capsid, and sometimes an outer envelope made of lipids.
17. An electron microscope can be used to see structures that are too small to be seen with an optical microscope, such as individual molecules and atoms.
18. An optical microscope can be used to observe living cells and tissues, while an electron microscope cannot because the sample must be fixed, dehydrated, and coated with a thin layer of metal before it can be observed.
19. An electron microscope has a better resolution than an optical microscope because it uses electrons instead of light to form an image, and electrons have much shorter wavelengths than light waves.
20. Cell fractionation is a laboratory process that can be used to separate the organelles within a cell.
21. The stages of mitosis in order are prophase, prometaphase, metaphase, anaphase, and telophase.
22. When observing a cell under a microscope, you can tell if it is undergoing mitosis by looking for visible changes in the nucleus and the appearance of the chromosomes. During prophase, the chromatin condenses into visible chromosomes and the nuclear envelope breaks down. During metaphase, the chromosomes line up along the equator of the cell. During anaphase, the sister chromatids are separated and pulled to opposite poles of the cell. During telophase, the nuclear envelope reforms around the separated chromosomes.
23. During metaphase, the chromosomes line up along the equator of the cell.
24. During anaphase, the sister chromatids are separated.
25. The spindle fibers, which are made up of microtubules and associated proteins, are needed for the separation of sister chromatids during anaphase.
26. During prophase, the chromatin condenses into visible chromosomes and the nuclear envelope breaks down. The spindle fibers begin to form from the centrosomes, which move towards opposite poles of the cell.
27. Bacteria carry out a different cell cycle called binary fission.
28. The two steps of bacterial cell division are DNA replication and cytokinesis.
29. Viruses replicate by invading a host cell and using its machinery to produce new virus particles. The virus attaches to a specific receptor on the surface of the host cell and injects its genetic material into the cell. The viral genetic material then takes over the host cell's machinery to produce new virus particles, which are assembled and released from the host cell to infect new cells.