Chapter 4

Question 1

is the structural and functional unit of all living things

Answer 1

cell

Question 2

contains genetic material, DNA, sections of which are called genes

Answer 2

nucleus

Question 3

the control center of the cell, is necessary for cell reproduction

Answer 3

nucleus

Question 4

genetic material that is loosely dispersed throughout the nucleus in a threadlike form

Answer 4

chromatin

Question 5

chromatin that has coiled and condensed forming dense, rodlike bodies

Answer 5

chromosomes

Question 6

small spherical bodies within the nucleus composed primarily of proteins and RNA

Answer 6

nucleoli

Question 7

assembly sites for ribosomes that are particularly abundant in the cytoplasm

Answer 7

nucleoli

Question 8

surrounds the nucleus; is double layered porous membrane

Answer 8

nuclear envelope

Question 9

the nuclear envelope has large ___ ____ that regulate what passes through

Answer 9

nuclear pores

Question 10

separates the cell contents from the surrounding environment, providing a protective barrier

Answer 10

plasma membrane

Question 11

membrane that is a bilayer of phospholipid molecules in which the protein molecules float

Answer 11

plasma membrane

Question 12

the plasma membrane is selective about what passes through it, this is known as

Answer 12

selective permeability

Question 13

tiny fingerlike projections/folds

Answer 13

microvilli

Question 14

organelles translates to

Answer 14

small organs

Question 15

Tiny spherical bodies composed of RNA and protein; floating free or attached to a membranous structure (the rough ER) in the cytoplasm. Actual sites of protein synthesis.

Answer 15

ribosomes

Question 16

membranous system of tubules that extends throughout the cytoplasm

Answer 16

endoplasmic reticulum

Question 17

studded with ribosomes, tubules of this organelle provide area for storage and transport of the proteins made on the ribosomes to other cell areas

Answer 17

rough ER

Question 18

no function of protein synthesis, is the site of steroid and lipid synthesis, lipid metabolism, and drug detoxification

Answer 18

smooth ER

Question 19

stack of flattened sacs with bulbous ends and associated small vesicles; found close to the nucleus

Answer 19

golgi apparatus

Question 20

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

Answer 20

golgi apparatus

Question 21

membranous sacs containing digestive enzymes including acid and hydrolyses; function is to digest worn-out cell organelles and foreign substances that enter the cell

Answer 21

lysosomes

Question 22

membranous sacs containing oxidase enzymes that detoxify alcohol, free radicals, and other harmful chemical

Answer 22

peroxisomes

Question 23

rod-shaped bodies with double membrane wall; contains enzymes that oxidize foodstuffs to produce ATP; powerhouse of the cell

Answer 23

mitochondria

Question 24

paired, cylindrical bodies composed of microtubules and are part of the centrosome; they direct the formation of the mitotic spindle during cell division

Answer 24

centrioles

Question 25

internal scaffolding that provides cellular support and functions in intracellular transport

Answer 25

cytoskeleton

Question 26

formed largely of actin, a contractile protein, and are important in cell mobility

Answer 26

microfilaments

Question 27

stable elements composed of a variety of proteins and resist mechanical forces action on cells

Answer 27

intermediate filaments

Question 28

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

Answer 28

microtubules

Question 29

longer period during which the cell grows and carries out its usual activities

Answer 29

interphase

Question 30

the period when the cell reproduces itself by dividing

Answer 30

cell division or mitotic phase

Question 31

during this phase, the cell is about to divide and the DNA is copied exactly

Answer 31

interphase

Question 32

is essential for growth and repair

Answer 32

cell division

Question 33

consists of two events, mitosis and cytokinesis

Answer 33

M phase ; mitosis

Question 34

is the division of the copied DNA of the mother cell to two daughter nuclei

Answer 34

mitosis

Question 35

is the division of the cytoplasm

Answer 35

cytokinesis

Question 36

the product of mitosis is two ____ _____ that are genetically identical to the m other nucleus

Answer 36

daughter nuclei

Question 37

yields four daughter nuclei that differ genetically in composition from the mother nucleus; used for sexual reproduction

Answer 37

meiosis

Question 38

part of interphase where the centrioles begin replicating

Answer 38

G1

Question 39

part of interphase when DNA is replicated

Answer 39

S phase

Question 40

final part of interphase where final preparations for mitosis are completed and centrioles finish replicating

Answer 40

G2

Question 41

is the first phase of mitosis

Answer 41

prophase

Question 42

chromatin condenses forming chromosomes; the nucleoli disappear, centrosomes separate from one another

Answer 42

early prophase

Question 43

centrosomes act as a focal point for growth of a microtubule assembly called the

Answer 43

mitotic spindle

Question 44

microtubules lengthen and, they propel the centrosomes towards opposite poles of the cell

Answer 44

early prophase

Question 45

microtubules arrays extend from the centrosome matrix

Answer 45

asters

Question 46

the nuclear envelope breaks up; the kinetochore microtubules pull on each chromosome from the poles and ultimately draws the chromosomes to the center

Answer 46

late prophase

Question 47

the second phase of mitosis

Answer 47

metaphase

Question 48

phase where the chromosomes cluster at the midline of the cell with centromeres aligned at the equator

Answer 48

metaphase

Question 49

the third and shortest phase of mitosis

Answer 49

anaphase

Question 50

the sister chromatids separate from each other and are pulled towards opposite ends of the cell. The protein “glue” that holds the sister chromatids together is broken down, allowing them to separate. Each is now its own chromosome. The chromosomes of each pair are pulled towards opposite ends of the cell.

Answer 50

anaphase

Question 51

the final phase of mitosis

Answer 51

telophase

Question 52

the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During telophase, a nuclear membrane forms around each set of chromosomes to separate the nuclear DNA from the cytoplasm.

Answer 52

telophase

Question 53

the cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.; forms the cleavage furrow and pinches the cell apart

Answer 53

cytokinesis