Chapter 3

Question 1

cell

Answer 1

the structural and functional unit of all living things

Question 2

nucleus

Answer 2

control center of the cell, necessary for cell division or cell replication

Question 3

plasma membrane

Answer 3

separates cell contents from the surrounding environment, made of a phospholipid bilayer

Question 4

chromatin

Answer 4

when the cell is not dividing, the genetic material is a threadlike form

Question 5

chromosomes

Answer 5

when a cell is dividing to form daughter cells, the chromatin coils and condenses to form darkly staining rodlike bodies

Question 6

nucleoli

Answer 6

small round bodies that are assembly bodies for ribosomes

Question 7

nuclear membrane

Answer 7

a double-layered porous membrane that surrounds the nucleus

Question 8

ribosomes

Answer 8

tiny spherical bodies composed of RNA and protein; actual sites of protein synthesis; seen floating for or attached to a membranous structure (the rough ER) in the cytoplasm

Question 9

endoplasmic reticulum

Answer 9

membranous system of tubules that extends throughout the cytoplasm; two varieties: (1) rough ER- studded with ribosomes (tables of the rough ER provide an area for proteins made un ribosomes to be transported to other cell areas; external face synthesizes phospholipids and cholesterol) and (2) smooth ER- a site of steroid and lipid synthesis, lipid metabolism, and a drug detoxification (no protein synthesis-related function)

Question 10

golgi apparatus

Answer 10

plays a role in packaging proteins or other substances for export from the cell or incorporation into the plasma membrane and in packaging lysosomal enzymes

Question 11

lysosomes

Answer 11

act to digest worn-out cell organelles and foreign substances that enter the cell

Question 12

peroxisomes

Answer 12

containing oxidase enzymes that detoxify alcohol, hydrogen peroxide, and other harmful chemicals

Question 13

mitochondria

Answer 13

contain enzymes that oxidize foodstuffs to produce cellular energy (ATP)

Question 14

centrioles

Answer 14

direct the formation of the mitotic spindle during cell division; form the bases of cilia and flagella

Question 15

cytoskeletal elements

Answer 15

provide cellular support, function in intracellular transport

Question 16

microtubules

Answer 16

form the internal structure of the centrioles and help determine cell shape

Question 17

intermediate filaments

Answer 17

stable elements composed of a variety of proteins, resists mechanical forces acting on cells

Question 18

microfilaments

Answer 18

formed largely of actin, are important in cell mobility