Chapter 8

Question 1

basic unit of all forms of life

Answer 1

cell

Question 2

fundamental concept of biology that states that all living things are composed of cells; that cells are the basic units of structure and function in living things; and that new cells are produced from existing cells

Answer 2

cell theory

Question 3

thin, flexible barrier that surrounds all cells; regulates what enters and leaves the cell

Answer 3

cell membrane

Question 4

in cells, structure that contains the cell’s genetic material in the form of DNA

Answer 4

nucleus

Question 5

organism whose cells contain a nucleus

Answer 5

eukaryote

Question 6

unicellular organism that lacks a nucleus

Answer 6

prokaryote

Question 7

fluid portion of the cell outside the nucleus

Answer 7

cytoplasm

Question 8

cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell; the site of protein synthesis

Answer 8

ribosomes

Question 9

internal membrane system found in eukaryotic cells; place where lipid components of the cell membrane are assembled

Answer 9

endoplasmic reticulum

Question 10

organelle in cells that modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell

Answer 10

golgi apparatus

Question 11

cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Answer 11

vacuole

Question 12

cell organelle that breaks down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell

Answer 12

lysosome

Question 13

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

Answer 13

chloroplast

Question 14

cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use

Answer 14

mitochondrion

Question 15

strong, supporting layer around the cell membrane in some cells

Answer 15

cell wall

Question 16

macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes

Answer 16

lipid

Question 17

property of biological membranes that allows some substances to pass across it while others cannot; also called semipermeable membrane

Answer 17

selectively permeable

Question 18

relatively constant internal physical and chemical conditions that organisms maintain

Answer 18

homeostasis

Question 19

process by which particles tend to move from an area where they are more concentrated to an area where they are less concentrated

Answer 19

diffusion

Question 20

diffusion of water through a selectively permeable membrane

Answer 20

osmosis

Question 21

when the concentration of two solutions is the same

Answer 21

isotonic

Question 22

when comparing two solutions, the solution with the greater concentration of solutes

Answer 22

hypertonic

Question 23

when comparing two solutions, the solution with the lesser concentration of solutes

Answer 23

hypotonic

Question 24

group of similar cells that perform a particular function

Answer 24

tissue

Question 25

group of tissues that work together to perform closely related functions

Answer 25

organ

Question 26

group of organs that work together to perform a specific function

Answer 26

organ system