Biology I
Chapters 4-8 Terms
Chapter 4 Terms
1. cell: (p. 11) a membrane-bound structure that is the basic unit of life.
2. cell membrane: (p. 59) the lipid bilayer that forms the outer boundary of a cell.
3. cell theory: (p. 69) the theory that all living things are made up of cells, that cells are the basic
units of organisms, and that cells come only from existing cells.
4. cell wall: (p. 82) a rigid structure that surrounds the cells of plants, fungi, many protests, and
most bacteria.
5. chloroplast: (p. 83) a plastid containing chlorophyll; the site of photosynthesis.
6. chromosome: (p. 81)DNA and protein in a coiled, rod-shaped form that occurs during cell
division.
7. cilium: (p. 80) a short, hair-like organelle that extends from a cell and functions in locomotion
or in the movement of substances across the cell surface.
8. cytoplasm: (p. 75) the region of a cell between the cell membrane and the nucleus.
9. endoplasmic reticulum: (p. 77) a system of membranous tubules and sacs in eukaryotic cells
that functions as a path along which molecules move from one part of the cell to another.
10. eukaryote: (p. 72) a cell that contains a nucleus and membrane-bound organelles.
11. flagellum: (p. 80) a hair-like structure made up of microtubules that function in locomotion.
12. Golgi apparatus: (p. 78) a system of membranes in eukaryotic cells that modifies proteins for
export by the cell
13. lysosome: (p. 79) an organelle containing digestive enzymes, existing primarily in animal cells.
14. mitochondrion: (p. 76) the organelle that is the site of aerobic respiration in eukaryotic cells.
15. nuclear envelope: (p. 80) a double membrane that surrounds the nucleus of a eukaryotic cell.
16. nucleolus: (p. 81) the structure in which ribosomes are synthesized and partially assembled;
found in most nuclei
17. nucleus: (p 32) in an atom; the core of protons and neutrons; in a eukaryotic cell, the organelle
that contains most of the DNA and directs most of the cell’s activities.
18. organelle: (p. 71) one of several formed bodies with a specialized function that is suspended in
the cytoplasm and found in eukaryotic cells.
19. plastid: (p. 83) an organelle of plant cells that contains starch, fats, or pigments.
20. prokaryote: (p. 72) a unicellular organism that lacks a nucleus and membrane-bound
organelles.
21. ribosome: (p. 77) an organelle that functions in the synthesis of proteins.
22. selectively permeable membrane: (p. 73) membrane that keeps out some molecules but
allows others to pass through.
23. spindle fibers: (p. 150) one of the microtubules that extend across a dividing eukaryotic cell;
assists in the movement of chromosomes.
24. vacuole: a fluid-filled organelle that stores enzymes or metabolic wastes in a plant cell.
Chapter 5 Terms
1. contractile vacuole: (p. 97) an organelle in protests that expels water
2. diffusion: (p. 95) the process by which molecules move from an area of greater concentration
to an area of lesser concentration.
3. osmosis: (p. 96) the diffusion of water across a selectively permeable membrane.
4. phagocytosis: (p. 103) a type of endocytosis in which a cell engulfs large particles or whole
cells.
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Biology I
Chapters 4-8 Terms
5. pinocytosis: (p. 103) a type of endocytosis in which a cell engulfs solutes or fluids.
6. turgor pressure: (p 98) water pressure within a plant cell.
Chapter 6 Terms
1. adenosine diphosphate (ADP): (p. 116) a substance involved in energy metabolism formed by
the breakdown of adenosine triphosphate.
2. ATP synthase: (p. 116) an enzyme that catalyzes the synthesis of ATP from ADP and
phosphate.
3. carotenoid: (p. 113) a light-absorbing compound that functions as an accessory pigment in
photosynthesis
4. light reactions: (p. 112) the initial reactions in photosynthesis, including the absorption of light
by photosystems I and II, the passage of electrons along the electron transport chains, the
production of NADPH and O2, and the synthesis of ATP through chemiosmosis.
5. photosynthesis: (p. 111) the conversion of light energy into chemical energy stored in organic
compounds.
6. pigment: (p. 112) in plants, a compound that absorbs light and imparts color.
7. stoma: (p. 119) one of many small pores usually located on the underside of a leaf; aids in gas
exchange.
Chapter 7
1. alcoholic fermentation: (p. 129) the process by which pyruvic acid is converted to ethyl
alcohol; the anaerobic action of yeast on sugars.
2. anaerobic pathway: (p. 128) the fermentation pathways
3. cellular respiration: (p. 127) the process in which cells make ATP by breaking down organic
compounds.
4. glycolysis: (p. 127) a pathway in which glucose is oxidized to pyruvic acid.
5. lactic acid fermentation: (p. 129) the process by which pyruvic acid is converted to lactic
acid.
6. pyruvic acid: (p. 128) a three-carbon molecule that is the end product of glycolysis.
7. aerobic respiration: (p. 133) the process in which cells make ATP by breaking down organic
compounds, with oxygen as the final electron acceptor.
8. Krebs cyle: (p. 133) a series of biochemical reactions that release carbon dioxide and results in
the formation of ATP.
Chapter 8
1. anaphase: (p. 150) a phase of mitosis and meiosis in which the chromosomes separate.
2. asexual reproduction: (p. 156) the production of offspring that does not involve the union of
gametes.
3. cell plate: (p. 151) a membrane that divides newly forming plant cells following mitosis.
4. centriole: (p. 150) a structure that appears during mitosis in animal cells.
5. centromere: (p. 146) a region of the chromosome where the two sister chromatids are held
together and which is the site of attachment of the chromosomes to the spindle fibers during
mitosis.
6. chromatid: (p. 146) one of two identical parts of a chromosome.
7. crossing-over: (p. 153) the exchange of genes by reciprocal segments of homologous
chromosomes during meiosis.
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Biology I
Chapters 4-8 Terms
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
cytokinesis: (p. 149) the division of the cytoplasm of one cell into two new cells.
diploid: (p. 147) a cell that contains both chromosomes of a homologous pair.
haploid: (p. 147) having only one chromosome of each homologous pair.
homologous chromosome: (p. 146) one of a pair of morphologically similar chromosomes.
interphase: (p. 149) a period of cell growth and development that precedes eukayotic cell
nuclear division.
meiosis: (p. 148) the process of nuclear division that reduces the number of chromosomes in a
cell by half.
metaphase: (p. 150) the second phase of mitosis, during which all the chromosomes move to
cell’s equator
mitosis: (p. 148) eukaryotic nuclear division
prophase: (p. 150) the first stage of mitosis and meiosis, characterized by condensation of
chromosomes.
synapsis: (p. 153) the pairing of homologous chromosomes during meiosis.
telophase: (p 151) the final stage of mitosis during which a nuclear membrane forms around
each set of new chromosomes.
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