cellular level organization set 4

Question 1

Most of the surface area of the cell membrane consists of

Answer 1

lipids

Question 2

Because of its chemical-structural composition, the cell membrane is called a

Answer 2

phospholipid bilayer

Question 3

The primary components of the cytoskeleton, which gives the cell strength and rigidity and anchors the position of major organelles, are

Answer 3

microtubules

Question 4

Most of the energy a cell needs to live is generated by the

Answer 4

mitochondria

Question 5

The major factor that allows the nucleus to control cellular operations is its

Answer 5

regulation of protein synthesis

Question 6

Ribosomal proteins and RNA are produced primarily in the

Answer 6

nucleolus

Question 7

Along the length of the DNA strand, information is stored in the sequence of

Answer 7

nitrogen bases

Question 8

A sequence of three nitrogen bases can specify the identity of

Answer 8

a single amino acid

Question 9

The process in which RNA polymerase uses the genetic information to assemble a strand of mRNA is

Answer 9

transcription

Question 10

If the DNA triplet is TAG, the corresponding codon on the mRNA strand will be

Answer 10

AUC

Question 11

Passive or leakage channels within the cell membrane permit

Answer 11

water and ion movement at all times

Question 12

Ions and other small water-soluble materials cross the cell membrane only by passing through

Answer 12

a receptor protein

Question 13

All transport through the cell membrane can be classified as either

Answer 13

active or passive

Question 14

The major difference between diffusion and bulk flow is that when molecules move by bulk flow they move

Answer 14

as a unit in one direction

Question 15

The rate that solute molecules are filtered depends on

Answer 15

their size, the force of hydrostatic pressure, rate of water passing through membrane

Question 16

The transmembrane potential is important in maintaining cell integrity because

Answer 16

it increases cell environment sensitivity.

Question 17

The factor(s) that interact(s) to create and maintain the transmembrane potential is (are) the

Answer 17

membrane permeability for sodium and potassium, presence of Na-K exchange pump

Question 18

The correct sequence of the cell cycle beginning with interphase is

Answer 18

G0, G1, S, G2, Gm

Question 19

As the cell life cycle proceeds, cyclin levels climb, causing the maturation promoting factor (MPG) to appear in the cytoplasm, initiating the process of

Answer 19

mitosis

Question 20

The spreading process of a primary tumor is called _____, and the dispersion of malignant cells to establish a secondary tumor is called _____.

Answer 20

invasion; metastasis

Question 21

The process of differentiation resulting in the appearance of characteristic cell specializations involves

Answer 21

gene repression (switching off)

Question 22

Homeostasis at the tissue, organ, system, and individual levels reflects

Answer 22

the combined and coordinated actions of many cells

Question 23

Structurally, the cell membrane is best described as a

Answer 23

phospholipid bilayer interspersed with proteins

Question 24

Isolating the cytoplasm from the surrounding fluid environment by the cell membrane is important because

Answer 24

cytoplasm’s composition differs from extracellular fluid and differences must be maintained

Question 25

Regulation of exchange with the environment is an important function of the cell membrane because it controls

Answer 25

the entry of ions and nutrients, and waste elimination

Question 26

Which type of vesicular transport uses pseudopodia to surround a solid object

Answer 26

phagocytosis

Question 27

Membranous organelles differ from nonmembranous organelles in that membranous organelles are ________.

Answer 27

surrounded by lipid membranes that isolate them from the cytosol

Question 28

The major functional difference between flagella and cilia is that flagella

Answer 28

move a cell through the surrounding fluid

Question 29

The smooth ER (SER) has a variety of functions that center around the synthesis of

Answer 29

lipids and carbohydrates

Question 30

The reason lysosomes are sometimes called "cellular suicide packets" is

Answer 30

the breakdown of lysosomal membranes can destroy a cell

Question 31

The energy-producing process in the mitochondria involves a series of reactions in which __________ is consumed and __________ is generated

Answer 31

oxygen; carbon dioxide

Question 32

The most notable characteristic of the G0 phase of an interphase cell is that

Answer 32

it is not preparing for mitosis

Question 33

The replication of DNA occurs primarily during the

Answer 33

S phase

Question 34

The process of cytokinesis refers to

Answer 34

the physical separation of the daughter cells

Question 35

The passive factor which helps to maintain the transmembrane potential is

Answer 35

K+ diffuse out of the cell faster than Na+ can enter and the interior of the cell develops an excess of negative charges

Question 36

The reason that dead skin cells are usually shed in thick sheets rather than individually is because of

Answer 36

the strength of the links of the desmosomes

Question 37

The reason that water-soluble ions and molecules cannot enter certain regions of the cell membrane is because of

Answer 37

the presence of hydrophobic tails on the interior of the membrane

Question 38

The effect of diffusion in body fluids is that it

Answer 38

tends to eliminate local concentration gradients

Question 39

During osmosis water will always flow across a membrane toward the solution that has the

Answer 39

highest concentration of solutes

Question 40

A solution that is hypotonic to cytoplasm has

Answer 40

a solute concentration lower than that of the cytoplasm

Question 41

Red blood cells are hemolyzed when the cells are placed in contact with

Answer 41

a hypotonic solution

Question 42

An injection of a concentrated salt solution into the circulatory system would result in

Answer 42

crenation of the red blood cells

Question 43

Facilitated diffusion differs from ordinary diffusion in that

Answer 43

carrier proteins are involved

Question 44

One of the great advantages of moving materials by active transport is

Answer 44

the process is not dependent on a concentration gradient

Question 45

In the human body, the process of phagocytosis is illustrated by

Answer 45

a white blood cell engulfing a bacterium

Question 46

Epsom salts exert a laxative effect due to the process of

Answer 46

osmosis

Question 47

The formation of a malignant tumor indicates that

Answer 47

mitotic rates of cells are no longer responding to normal control mechanisms

Question 48

Which organelle absorbs and breaks down fatty acids and other organic compounds?

Answer 48

peroxisome

Question 49

Protein channels within the cell membrane

Answer 49

permit water and ion movement at all times

Question 50

A sequence of three nucleotide bases in the mRNA is called a(n) ________.

Answer 50

codon

Question 51

What is the functional unit of heredity?

Answer 51

gene

Question 52

Which of the following is an important characteristic of the transmembrane potential?

Answer 52

The ions held on either side of the cell membrane have potential energy.

Question 53

In which phase does a cell make enough organelles for two functional cells?

Answer 53

G1

Question 54

In which phase does centriole replication complete?

Answer 54

G2

Question 55

The cell membrane isolates the cytoplasm from the surrounding fluid environment. Why is this important?

Answer 55

Cytoplasm has a composition different from that of the extracellular fluid, and the differences must be maintained.

Question 56

Cilia function to ________.

Answer 56

move fluids or secretions across the cell surface

Question 57

Which of the following influences diffusion rates?

Answer 57

distance, temperature, and molecular size

Question 58

Water-soluble ions and molecules CANNOT enter certain regions of the cell membrane because of ________.

Answer 58

the presence of hydrophobic tails on the interior of the membrane

Question 59

The difference between an area of high concentration and an area of low concentration is known as ________.

Answer 59

a concentration gradient