learnsmart

Question 1

the plasma membrane is made up of 3 types of lipids. what are they?

Answer 1

cholesterol, phospholipids & glycolipids

Question 2

which of the following is false regarding the cell membrane?

Answer 2

it is made primarily of cytosol

Question 3

a type of steroid called __ is scattered within the hydrophobic regions of the phospholipid bilayer, where it strengthens the membrane and stabilizes it at extreme temperatures

Answer 3

cholesterol

Question 4

forms of passive transport across cell membranes include __

Answer 4

osmosis and diffusion

Question 5

the 2 major categories of membrane transport are __ transport that requires no energy expenditure and __ transport

Answer 5

passive; active

Question 6

__ is a passive form of transport

Answer 6

simple diffusion

Question 7

ion movement through small proteins in the membrane is an example of __ diffusion

Answer 7

channel-mediated

Question 8

__ is required for osmosis to occur

Answer 8

a selectively permeable membrane

Question 9

when water moves across a semi-permeable membrane, the pressure it experts is __ pressure

Answer 9

osmotic

Question 10

the sodium-potassium exchange pump transports __ (number) sodium ions out of the cell for every __ (number) potassium ions it transports into the cell

Answer 10

3 Na+ ions are pumped out of a cell for every 2 K+ ions that are pumped into a cell

Question 11

the net movement of a substance from high concentration to low is called __

Answer 11

diffusion

Question 12

K+ movement out of the cell is facilitated by its __ __ gradient but opposed by the __ gradient

Answer 12

chemical concentration

electrical

Question 13

sodium ions enter the cell through sodium __ channels as they move down their concentration gradient

Answer 13

leak

Question 14

neurons have a resting membrane potential of __ mv

Answer 14

-70

Question 15

the __ gradient is dependent on the combination of the __ gradient and the chemical concentration gradient

Answer 15

electrochemical

electrical

Question 16

which statements characterize organelles?

Answer 16

each type of organelle differs in shape

each type of organelle has a specific function

they are generally located within cells

Question 17

the synthesis of steroid hormones occurs in the __

Answer 17

smooth er

Question 18

the primary structure for the processing and packaging of proteins for transport out of the cell is the __

Answer 18

Golgi apparatus

Question 19

lysomes remove old organelles through a process called __

Answer 19

autophagy

autos- self
phago- to eat

lysomes digest molecular structures of damaged organelles

Question 20

the organelle that has a double membrane, its own small piece of DNA, and synthesizes ATP is the __

Answer 20

mitochondrion

Question 21

when a protein is marked for destruction by having a protein called ubiquitin bound to it, the organelle responsible for this removal are __

Answer 21

proteasomes

Question 22

true or false: cilia and flagella are projections that extend from the surface of some cells

Answer 22

true

Question 23

which statements characterize microvilli?

Answer 23

they are smaller than cilia

function to increase surface area of plasma membrane

they are microscopic projections of plasma membrane

Question 24

the 3 major types of membrane junctions are __ junctions, desmosomes and gap junctions

Answer 24

tight

Question 25

intestinal cells are joined by _ in order to prevent digestive juices from moving between and damaging adjacent cells

Answer 25

tight junctions

Question 26

gap junctions are bridged by proteins called __

Answer 26

connexons

Question 27

the nucleus is enclosed by a double membrane structure called the __

Answer 27

nuclear envelope

Question 28

which statements describe chromosomes?

Answer 28

they contain DNA & proteins they are more condensed than chromatin

Question 29

chromatin is composed of __

Answer 29

DNA and proteins

Question 30

a typical cell has how many nuclei?

Answer 30

1

Question 31

the relative distributions of K+, which is more concentrated inside the cell and Na+, which is more concentrated outside the cell are the result of the activity of the __

Answer 31

Na+/K+ pump

Question 32

the plasma membrane also functions in establishing and maintaining an electrochemical gradient at the plasma membrane called the __

Answer 32

resting membrane potential

Question 33

__ are complex, organized structures inside the cells; they have unique characteristics and shapes

Answer 33

organelles

Question 34

transport (shuttle) vesicles are produced within a cell by __

Answer 34

rough ER

Question 35

the 2 types of organelles found in cells are __ -bound and __ -bound

Answer 35

membrane-bound non-membrane bound

Question 36

microtubules

Answer 36

move chromosomes during cell division

Question 37

cilia

Answer 37

move fluid, mucus, and materials over the cell surface

Question 38

flagellum

Answer 38

propels sperm cells of human male

Question 39

microvilli

Answer 39

increase membrane surface area for increased absorption and/or secretion

Question 40

__ is a general function performed by all cells

Answer 40

to obtain nutrients

Question 41

which of the following describe the general functions of the cell?

Answer 41

* obtain nutrients * dispose of wastes * maintain shape of cell

Question 42

which of the following statements are true regarding integral proteins?

Answer 42

they act as identity markers for the cell they can act as membrane channels they can act as receptors

Question 43

rapid digestion of a cell by its own lysosomes is called __

Answer 43

autolysis

Question 44

true or false: in transcription a DNA gene is read and copied to produce a newly formed strand of DNA

Answer 44

false

Question 45

the process by which a DNA gene is copied into RNA

Answer 45

transcription

Question 46

the 3 functional types of RNA produced during transcription are messenger RNA, transfer RNA and __ RNA

Answer 46

ribosomal

Question 47

the process that occurs on ribosomes by which a mRNA transcript is read and a nee protein produced is called

Answer 47

translation

Question 48

which are required for translation?

Answer 48

mRNA, amino acids | tRNA, ribosomes

Question 49

the primary cellular sites for the production of proteins are the __

Answer 49

ribosomes

Question 50

in the cell cycle, division of the nucleus is called __

Answer 50

mitosis

Question 51

in cell division, 1 cell divides to produce 2 identical cells called __

Answer 51

daughter cells

Question 52

__ proteins provide a means of regulating movement of substances across the plasma membrane

Answer 52

transport

Question 53

__ cells include all of the cells in the body except sex cells

Answer 53

somatic

Question 54

much of the internal content of the __ is the genetic material, DNA

Answer 54

nucleus

Question 55

when a cell is dividing the dna is tightly coiled as..

Answer 55

chromosomes

Question 56

the 3 components of the cytoplasm of a cell are..

Answer 56

cytosol, organelles, & inclusions

Question 57

which statements characterize smooth ER?

Answer 57

doesnt have ribosomes attached can detoxify drugs stores lipids

Question 58

the cell division that takes place in somatic cells

Answer 58

mitosis

Question 59

the microscope that moves an electron beam over the surface of a specimen is the..

Answer 59

scanning electron microscope

Question 60

the study of cells

Answer 60

cytology

Question 61

peroxisomes break down harmful substances including

Answer 61

hydrogen peroxide fatty acid molecules

Question 62

the __ is a general term for all cellular contents between

Answer 62

cytoplasm

Question 63

which statement(s) characterizes prophase?

Answer 63

the nuclear envelope disappears chromatin condenses into chromosomes it is the 1st stage of mitosis

Question 64

the cell structure that functions as a gatekeeper to regulate the passage of gases, nutrients, and wastes between the internal and external environments is the __

Answer 64

plasma membrane