Anatomy And Physiology Ch3

Front 1

The smallest unit of life is the________.

Back 1

cell

Front 2

The outer boundary of a human cell is the:

Back 2

plasma membrane.

Front 3

Which of the following would not be found in the plasma membrane of a human cell?

Back 3

Nucleic acids

Front 4

Tight junctions

Back 4

Prevent molecules from passing through the extracellular space between adjacent cells

Front 5

Desmosomes

Back 5

Anchoring junctions found in areas subjected to pulling forces

Front 6

Gap junctions

Back 6

Important for cell communication

Front 7

Water can readily diffuse through the plasma membrane.

Back 7

True

Front 8

Osmosis is:

Back 8

the diffusion of water across a cell membrane.

Front 9

Which of the following pairs is a correct match?

Back 9

Exocytosis: active transport

Front 10

A cell will swell, and likely burst, if it is placed in a __________ solution.

Back 10

hypotonic

Front 11

Primary active transport is driven by secondary active transport.

Back 11

False

In primary active transport, energy from ATP is used to drive the solute against a concentration gradient. In secondary active transport this is not the case. Energy from ATP is not used, but rather the electrochemical gradient or potential is used to drive the solute across the membrane. This involves the co-transport in the opposite direction of another solute. So one solute goes out of the cell while the other goes into the cell. This is secondary active transport.

Front 12

Pinocytosis is a type of___________.

Back 12

endocytosis

Front 13

Cells of the body mainly use _______ for the selective endocytosis of most macromolecules.

Back 13

receptor-mediated endocytosis

Front 14

At rest, most body cells are not polarized.

Back 14

False

Front 15

The primary site of cellular ATP production is the:

Back 15

mitochondrion.

Front 16

Ribosomes are found:

Back 16

in the cytosol and on the endoplasmic reticulum.

Front 17

Match the cell structure to its function. Ribosome

Back 17

Protein synthesis

Front 18

Nucleolus

Back 18

RNA synthesis

Front 19

Endoplasmic reticulum

Back 19

Protein folding, packaging, and modification

Front 20

Peroxisomes

Back 20

Neutralize dangerous free radicals

Front 21

Cytoskeleton

Back 21

Support cellular structures

Front 22

Lysosomes

Back 22

Contain digestive enzymes

Front 23

DNA is replicated during the ________ phase of the cell cycle.

Back 23

S-phase

Front 24

A gene is best defined as:

Back 24

a segment of DNA that carries instructions for the production of a polypeptide chain.

Front 25

During transcription:

Back 25

DNA is used as a template to make mRNA.

Front 26

Which of the following statements about living cells is false?


a) Most are microscopic
b) They are found in all animals but not in all plants.
c) They are the smallest basic units that can carry out all of the functions that we normally define as life.

Back 26

b) They are found in all animals but not in all plants.

All living things, including plants are made up of cells. However, comparatively simple things such as viruses do not have most of the components of cells nor are they technically living in the same sense as plants and animals.

Front 27

Chromosomes are found in _____________________ of cells.

Back 27

However, keep in mind that the chromosomes only become visible when a cell begins to divide.

Chromosomes are never found in the cytoplasm of a normal cell.

Front 28

Which of the following statements is true about the chromosomes of different plant and animal species?

Back 28

They may differ in number, shape, and size.

This fact provides a useful tool for biologists in distinguishing between species. For instance, humans have 46 chromosomes, while chimpanzees have 48. This number difference is one indication that we are not the same species.

Front 29

Which of the following statements is true about cells?

Back 29

The nuclear membrane acts as a selectively permeable barrier. That is to say, it allows some important substances to cross over while keeping the contents of the nucleus from spilling out into the cytoplasm.

Front 30

A karyotype is a:

Back 30

Karyotypes allow us to quickly see if an individual has any gross chromosomal abnormalities. For instance, this technique can be used to identify the genetically inherited condition known as Down`s syndrome.

A karyotype is neither a normal nor an abnormal chromosome. Karyotype is a term that does not apply to an individual chromosome.

Front 31

The sex chromosomes of normal females are:

Back 31

Females only have X sex chromosomes. Males, in contrast, inherit an X from their mother and a Y from their father. There are some individuals who have extra X`s and/or Y`s, but these are rare combinations.

Front 32

The sex chromosomes of females are ___________ and those of males are ___________ .

Back 32

The two X chromosomes in females carry the same genes. The X and Y chromosomes of males mostly do not. X chromosomes have many more genes for traits not related to sexuality which are expressed in the phenotypes of males even if they are recessive.

Front 33

Autosomes:

Back 33

The autosomes contain the genes that determine almost all of the non-gender inherited related traits. Most of our genetic inheritance comes from the genes in the autosomes.

Front 34

Normal humans have __________ pairs of autosomes and ___________ pairs of sex chromosomes.

Back 34

Humans normally inherit 22 autosomes and 1 sex chromosome from each parent. In total, we have 46 chromosomes in somatic cells--22 pairs of autosomes and 1 pair of sex chromosomes.

Front 35

All of the chromosomes in each normal human cell collectively have approximately __________ genes.

Back 35

20,000-25,000

There has been some controversy in past years about the actual number of human genes. However, most researchers now agree that about 20,000-25,000 is a fairly good estimate.

Front 36

A chromatid is:

Back 36

When a chromosome becomes visible just before cell replication, it has two or more chromatids that come together at a centromere. At other times, chromosomes are long, thin, thread-like structures that appear as an essentially undifferentiated mass.

Front 37

The development of masculine physical characteristics is most affected by the inheritance of:

Back 37

The SRY (or sex determining region Y) gene is necessary for an XY individual to develop male physical characteristics. Without it, female traits develop instead.

Front 38

A plasma-membrane lipid possessing a sugar chain that functions in cell recognition

Back 38

Glycolipid

Front 39

The most abundant molecule found within the lipid bilayer of the plasma membrane

Back 39

Phospholipid

Front 40

A plasma-membrane lipid that improves the rigidity of the plasma membrane and increases the membrane's impermeability to water

Back 40

Cholesterol

Front 41

The component of the plasma membrane that can act as a doorway for charged particles

Back 41

Protein

Front 42

The method by which large particles and macromolecules enter the cell by an infolding of the plasma membrane

Back 42

Endocytosis

Front 43

The movement of water across a selectively permeable plasma membrane from a region of high concentration to a region of low concentration

Back 43

Osmosis

Front 44

The mechanism by which substances are moved from the cell cytoplasm to the outside of the cell by the fusion of a vesicle with plasma membrane

Back 44

Exocytosis

Front 45

The tendency of molecules to move along their concentration gradient from a region of high concentration to a region of low concentration

Back 45

Diffusion

Front 46

These methods carry molecules, pump molecules, or form channels through which specific molecules pass across the plasma membrane

Back 46

Transport mechanisms

Front 47

Endocytosis of large items, such as bacteria or cellular debris

Back 47

Phagocytosis

Front 48

Endocytosis of a tiny quantity of extracellular fluid containing solute molecules

Back 48

Pinocytosis

Front 49

Endocytosis that utilizes selective plasma membrane receptor proteins

Back 49

Receptor-mediated endocytosis

Front 50

Hormones such as insulin, low-density lipoproteins

Back 50

Receptor-mediated endocytosis

Front 51

Water movement across membrane

Back 51

Osmosis

Front 52

Movement of oxygen, carbon dioxide, and other small uncharged molecules across membrane

Back 52

Diffusion

Front 53

Movement of large particles, bacteria, or cellular debris by endocytotic vesicle

Back 53

Phagocytosis

Front 54

Molecules moving against the concentration gradient

Back 54

Active transport mechanisms

Front 55

Mitochondrion

Back 55

Cristae; matrix

Front 56

Ribosome

Back 56

Composed of two subunits; can be "free" in the cytosol or attached to rough ER

Front 57

Rough endoplasmic reticulum

Back 57

Produces protein transport vesicles

Front 58

Golgi apparatus

Back 58

Possesses a cis and trans side; composed of cisternae

Front 59

Centrioles

Back 59

Composed of microtubules arranged in nine groups of three

Front 60

These thinnest members of the cytoskeleton are composed of strands of actin protein

Back 60

Microfilaments

Front 61

These cytoskeleton members are tough, insoluble protein fibers that possess a high tensile strength

Back 61

Intermediate filaments

Front 62

These hollow tubular members of the cytoskeleton are composed of spherical protein subunits called tubulin and can be quickly assembled and disassembled by the cell

Back 62

Microtubules

Front 63

Strands of DNA and associated histones in the nucleus of a non-dividing cell

Back 63

Chromatin

Front 64

Membrane that surrounds the nucleus of a cell

Back 64

Nuclear envelope, or nuclear membrane

Front 65

Tiny passageway that allows large molecules to freely pass in and out of the nucleus

Back 65

Nuclear pore

Front 66

Dark-staining body found in the nucleus of a cell that functions in producing ribosomes

Back 66

Nucleolus

Front 67

Jelly-like fluid found within the nucleus of a cell

Back 67

Nucleoplasm

Front 68

Dark-staining, rod-shaped structures composed of highly coiled chromatin, found in cells undergoing cell division

Back 68

Chromosomes

Front 69

Spherical protein molecules around which DNA wraps

Back 69

Histones

Front 70

Fine, uncoiled strands of DNA in the nucleus of a non-dividing cell

Back 70

Extended chromatin

Front 71

Dark-staining regions in the nucleus of a non-dividing cell composed of tightly coiled strands of DNA

Back 71

Condensed chromatin

Front 72

A section of DNA and its eight associated histone proteins

Back 72

Nucleosome

Front 73

The cell is metabolically active, synthesizing proteins, and growing rapidly
G2 B. Cell division enzymes are synthesized, and the centrioles complete replication
S C. DNA replicates itself

Back 73

G1 Phase

Front 74

Cell division enzymes are synthesized, and the centrioles complete replication

Back 74

G2 Phase

Front 75

S C. DNA replicates itself

Back 75

S Phase

Front 76

Metaphase

Back 76

Chromosomes line up along the cell equator

Front 77

Prophase

Back 77

Chromatin condenses into chromosomes; centrioles move toward opposite poles of the cell

Front 78

Anaphase

Back 78

Identical sets of chromosomes are moved to opposite sides of the cell

Front 79

Telophase

Back 79

Chromosomes uncoil and revert to chromatin; nuclear membranes form around the sets of chromosomes

Front 80

Ribosomes

Back 80

Protein synthesis

Front 81

Smooth endoplasmic reticulum

Back 81

Lipid synthesis

Front 82

Lysosomes

Back 82

Intracellular digestion

Front 83

Centrioles

Back 83

Organize the spindle during mitosis

Front 84

Microtubules

Back 84

Support the cell and give it shape; involved in cell movements

Front 85

Mitochondrion

Back 85

ATP

Front 86

Rough endoplasmic reticulum

Back 86

Transport vesicles

Front 87

Golgi apparatus

Back 87

Lysosomes and secretory vesicles

Front 88

Nucleolus

Back 88

Ribosomes

Front 89

Centrioles

Back 89

Cilia and flagella (microtubules)

Front 90

Cytokinesis

Back 90

Division of the parent cell cytoplasm into two daughter cells

Front 91

Mitosis

Back 91

Separation of two identical sets of chromosomes to opposite sides of the parent cell

Front 92

Interphase

Back 92

Non-dividing stage involving rapid growth, DNA replication, and preparation for division

Front 93

Diffusion

Back 93

Random motion of a substance resulting in movement from area of high to lower concentration

Front 94

Facilitated diffusion

Back 94

A passive process utilizing a protein carrier or channel

Front 95

Primary active transport

Back 95

Movement of a substance that utilizes a carrier; energy comes directly from hydrolysis of ATP

Front 96

Secondary active transport

Back 96

Movement of a substance that utilizes a carrier, and has a concentration gradient as the source of energy

Front 97

mRNA

Back 97

Carries genetic instructions from nucleus to the site of protein synthesis

Front 98

tRNA

Back 98

Uses an anticodon to guide its attached amino acid to the complementary codon on the mRNA at the ribosome

Front 99

rRNA

Back 99

Combines in a complex with proteins to make the large and small subunits of a ribosome

Front 100

microRNA

Back 100

Can control, or inhibit, certain genes

Front 101

Tight junction

Back 101

Adjacent cells joined by a line of membrane proteins that form an impermeable junction

Front 102

Desmosome

Back 102

Button-like junctions that use linker proteins to hold adjacent cells together

Front 103

Gap junctions

Back 103

Adjacent cells held together by connexon proteins that form cylinders allowing ion flow between the cells' cytoplasm

Front 104

Microvilli

Back 104

Tiny fingerlike projections of the plasma membrane; increase surface area for absorption

Front 105

Cilia

Back 105

Motile cellular extensions found in large numbers in some epithelial cells

Front 106

Flagella

Back 106

Long, cellular projections that are tail-like and aid in propulsion

Front 107

Hydrophobic

Back 107

Water fearing

Front 108

Hydrophilic

Back 108

Water loving

Front 109

Integral protein

Back 109

A protein that goes all the way through the cell membrane

Front 110

Peripheral protein

Back 110

A protein that is found on only one side of the cell membrane

Front 111

Hydrostatic pressure

Back 111

The force of a liquid pushing against something

Front 112

Osmotic pressure

Back 112

The force that solutes have to attract water

Front 113

Isotonic solution

Back 113

A solution containing equal solutes to the cell

Front 114

Hypertonic solution

Back 114

A solution containing more solutes than the cell

Front 115

Hypotonic solution

Back 115

A solution containing fewer solutes than the cell

Front 116

The process in which DNA's genetic code is copied onto messenger RNA molecules is known as translation.

Back 116

False
DNA's genetic code is copied onto messenger RNA molecules by a process known as transcription.

Front 117

The two major periods in the life cycle of a cell are interphase and the mitotic phase.

Back 117

True
The cell cycle can be divided into two major periods: interphase, in which the cell grows and carries on its usual activities, and the mitotic phase, during which the nucleus divides and cytokinesis forms two cells.

Front 118

The cytoskeleton refers to small calcium-containing macromolecular bones that are attached to muscle proteins.

Back 118

False

The cytoskeleton is comprised of microtubules, microfilaments, and intermediate filaments.

Front 119

The molecular composition of chromatin is DNA and histones.

Back 119

True
Chromatin is DNA and histone proteins.

Front 120

The glycocalyx is a coating of glycoproteins inside the cell membrane and guides organelles to their proper place in the cell.

Back 120

False
The glycocalyx refers to the sugar-coated outer surface of cells.

Front 121

Rough endoplasmic reticulum possesses ribosomes on its surface.

Back 121

True
Ribosomes are located on the external face of the membranes of rough endoplasmic reticulum, giving it a rough appearance.

Front 122

Lysosomes are produced by the smooth endoplasmic reticulum.

Back 122

False
The Golgi apparatus produces two membrane-bound vesicles, including the secretory vesicles and the lysosomes.

Front 123

Living things can arise by spontaneous generation.

Back 123

False
Life can only arise from preexisting life and NOT by spontaneous generation.

Front 124

Ribosomes are made of one type of RNA and use other types of RNA in the process of making proteins.

Back 124

True
Ribosomes are made of rRNA and use tRNA and mRNA to make proteins.

Front 125

Diffusion is the movement of molecules from a region of high concentration to a region of low concentration.

Back 125

True
Molecules move along a concentration gradient from a region where they are more concentrated, to a region where they are less concentrated, by their own kinetic energy.

Front 126

Diffusion is the movement of molecules from a region of high concentration to a region of low concentration.

Back 126

True
Molecules move along a concentration gradient from a region where they are more concentrated, to a region where they are less concentrated, by their own kinetic energy.

Front 127

Cytokinesis is the process that divides the cell nucleus into two nuclei.

Back 127

False
Cytokinesis is the division of the parent cell cytoplasm into two daughter cells.

Front 128

Centrioles are paired organelles found in the centrosome and function in organizing microtubules.

Back 128

True
Paired centrioles, located in the centrosome, are composed of 27 microtubules, arranged in nine sets of three, and function in forming cilia.

Front 129

Cell differentiation produces different types of cells with distinct features and functions.

Back 129

True
From a single fertilized egg, over 200 different cell types, each with specific features and functions, are produced in the human body.

Front 130

All substances can pass freely between the intracellular and extracellular fluids through a selectively permeable membrane.

Back 130

False
Only small, uncharged molecules and lipid -soluble molecules can pass freely between the intracellular and extracellular fluids through a selectively permeable membrane.

Front 131

RNA is the material stored in the nucleus and contains genes.

Back 131

False
DNA is the basic genetic material.

Front 132

What are footloose cells in the human body?

Back 132

A term used to describe cells that are not bound together in tight-knit communities.

Examples of "footloose" cells are blood, sperm, and some phagocytic cells.

Front 133

Which of the following statements best describes the fluid mosaic model of the plasma membrane?

Back 133

A lipid bilayer with protein molecules dispersed within it

The fluid mosaic model of the plasma membrane is composed of two layers of lipid molecules with protein molecules dispersed within.

Front 134

Which item below is NOT a function performed by proteins found in the plasma membrane?

Back 134

Synthesis of proteins

The synthesis of proteins is a function performed by ribosomes.

Front 135

In which stage of mitosis do the chromosomes align along the cell equator?

Back 135

Metaphase

In metaphase, the chromosomes cluster around the middle of the cell, with their centromeres aligned on the cell equator.

Front 136

Lysosomes perform which of the following cellular functions?

Back 136

Intracellular digestion

Lysosomes are spherical membrane-bound sacs that contain many different digestive enzymes utilized within the cell.

Front 137

Which of the following cell organelles produces secretory vesicles?

Back 137

Golgi apparatus

Secretory vesicles bud off of the trans-Golgi network of the Golgi apparatus and travel to the plasma membrane, where their contents are secreted.

Front 138

Which type of membrane transport process uses ATP as a source of energy?

Back 138

Primary active transport

Active transport processes use ATP. Notice the first letter in each word.

Front 139

Which of the following cell organelles function in supporting cellular structures and in generating cell movements?

Back 139

Cytoskeleton

The cytoskeleton is an elaborate network of rods running throughout the cytosol, functioning in supporting cellular structures and in generating cell movements.

Front 140

Which of the following cell organelles is responsible for generating the energy the cell uses to perform work?

Back 140

Mitochondrion

The mitochondrion transfers the energy found in nutrient molecules to ATP, the molecule that cells use to supply power for chemical reactions.

Front 141

Which of the following cell organelles possesses oxidase enzymes that function in neutralizing harmful free radicals?

Back 141

Peroxisome

Peroxisomes contain a wide variety of enzymes, including oxidases, which function in neutralizing harmful free radicals in the cells.

Front 142

Which of the following cell organelles serves as the site of protein synthesis?

Back 142

Ribosome

Amino acids are bonded together on the ribosomes to form protein molecules by a process known as translation.

Front 143

Which of the following molecular components of the lipid bilayer of the plasma membrane possesses a charged polar "head" and an uncharged non-polar "tail"?

Back 143

Phospholipid

The plasma membrane is composed primarily of phospholipid molecules that possess a charged polar "head" and an uncharged non-polar "tail" which prompts the molecules to align in a lipid bilayer.

Front 144

Which nucleic-acid molecules are involved in transcription but not translation in the synthesis of a particular polypeptide?

Back 144

DNA

DNA is copied into mRNA in transcription within the nucleus in the synthesis of a particular polypeptide.

Front 145

The mRNA start codon, AUG, matches up with a tRNA anticodon, _______.

Back 145

UAC

Front 146

Which of the following cell structures are involved in propelling substances across cell surfaces?

Back 146

Cilia

Cilia move in unison, creating a unidirectional current that propels substances across cell surfaces.

Front 147

Which of the following cell structures functions as the control center of the cell?

Back 147

Nucleus

The nucleus' genetic material, DNA, directs cellular activities by providing the instructions for protein synthesis.

Front 148

Which of the following is the correct sequence for the stages of mitosis?

Back 148

Prophase, metaphase, anaphase, telophase

The process of mitosis is composed of four continuous stages known as prophase, metaphase, anaphase, and telophase.

Front 149

Which of the following transport mechanisms involves the movement of water?

Back 149

Osmosis

Osmosis is the movement of water for a region of higher concentration to a region of lower concentration.

Front 150

Some cells are said to be sugar coated due to the presence of:

Back 150

glycocalyx.

The glycocalyx is made up of glycoproteins, which are proteins with carbohydrate side chains located on the outside surface of the cell membrane, thus causing the cell to be sugar coated.

Front 151

Proteins in the cell membrane that bind hormones and relay messages into the interior of the cell:

Back 151

perform a function known as signal transduction.

Carrier proteins bind to a substance and move the substance through the membrane.

Front 152

Definite changes in the _____________ of the cell membrane can be seen in a cell that is becoming cancerous.

Back 152

glycocalyx

Cholesterol provides strength to the plasma membrane and does not change when the cell becomes cancerous.

Front 153

All of the following cells are considered "foot loose," except:

Back 153

epithelial cells.

Epithelial cells are knitted into tight communities and have many membrane junctions between the cells.

Front 154

Which of the following are considered anchoring junctions?

Back 154

Desmosomes

Desmosomes are considered the anchoring junctions of adjacent cells.

Front 155

Simple diffusion is best described as substances:

Back 155

moving down a concentration gradient passively.

Moving substances from an area of high concentration to that of low concentration does not require energy and is known as simple diffusion.

Front 156

Crenation takes place when a cell is placed in a(n):

Back 156

hypertonic solution.
Cells placed in a hypotonic solution would rupture from an increase in the volume of water inside the cell.

Front 157

Vesicular transport is involved in all of the following transport processes, except:

Back 157

solute pumps.

Solute pumps are considered active transporters and can move large or small molecules.

Front 158

The resting membrane potential is mainly determined by the concentration gradient of ____ inside the cell.

Back 158

K+

The resting potential is mainly determined by the intracellular concentration gradient of potassium (K+)

Front 159

All of the following are functions of membrane receptors, except:

Back 159

cell adhesion.

Contact signaling is the function of membrane receptors that allows cells to recognize each other.

Front 160

"Cristae" are found in which of the following cell organelles?

Back 160

The mitochondria

The mitochondria contain cristae produced by the inward folding of its inner membrane.

Front 161

The underlying cause of Tay Sachs disease is:

Back 161

the lack of the enzymes needed to breakdown a glycolipid, which is abundant in nerve cell membranes.

This is not the cause of Tay Sachs disease.

Front 162

Which of the following types of RNA contains regions that act as a switch to turn protein synthesis on and off for the protein it codes for?

Back 162

Riboswitches

The tRNA selects and transports amino acids to the ribosome during protein synthesis.