cell

Question 1

The basic living unit of all organisms. The simplest organisms consist of single cells, whereas humans are composed of multiple cells.

Answer 1

cell

Question 2

an Organelle containing the cell’s genetic material.

Answer 2

nucleus

Question 3

The living material surrounding the nucleus and it contains many types of organelles. It enclosed by the cell membrane, or plasma membrane.

Answer 3

cytoplasm

Question 4

commonly defined as “the smallest units of life,”

Answer 4

cells

Question 5

The chemical reactions that occur within cells are collectively called cell metabolism. Energy released during metabolism is used for cell activities, such as the synthesis of new molecules, muscle contraction, and heat production, which helps maintain body temperature.

Answer 5

1. Cell metabolism and energy use

Question 6

The chemical reactions that occur within cells are collectively called cell metabolism. Energy released during metabolism is used for cell activities, such as the synthesis of new molecules, muscle contraction, and heat production, which helps maintain body temperature.

Answer 6

Cell metabolism and energy use

Question 7

the outermost component of a cell.

Answer 7

The cell membrane, or plasma (PLAZ-mah) membrane

Question 8

Substances outside the cell

Answer 8

extracellular substances

Question 9

inside the cell

Answer 9

cytoplasmic, or intracellular,

Question 10

Studies of the arrangement of molecules in the cell membrane have given rise to a model of its structure

Answer 10

fluid-mosaic model

Question 11

phosphate-containing ends of the phospholipids are hydrophilic (water-loving) and therefore face the extracellular fluid and cytoplasm of the cell.

Answer 11

polar

Question 12

fatty acid ends of the phospholipids are hydrophobic (water-fearing) and therefore face away from the fluid on either side of the membrane, toward the center of the double layer of phospholipids.

Answer 12

non polar

Question 13

selectively permeable, meaning that they allow some substances, but not others, to pass into or out of the cells.

Answer 13

Cell membranes

Question 14

generally composed of two major parts, solutes and the solvent.

Answer 14

solution

Question 15

substances dissolved in a predominant liquid or gas, which is called the solvent. Ions or molecules, are in constant motion.

Answer 15

solutes

Question 16

Each solute tends to move from an area where it is in higher concentration to an area where it is in lower concentration in solution.

Answer 16

diffusion

Question 17

results from the natural, constant random motion of all solutes in a solution.

Answer 17

Diffusion

Question 18

the difference in the concentration of a solute in a solvent between two points divided by the distance between the two points.

Answer 18

concentration gradient

Question 19

the diffusion of water across a selectively permeable membrane, such as the cell membrane, from a region of higher water concentration to one of lower water concentration

Answer 19

Osmosis

Question 20

is important to cells because large volume changes caused by water movement can disrupt normal cell functions. Occurs when the cell membrane is less permeable, selectively permeable, or not permeable to solutes and a concentration gradient for water exists across the cell membrane.

Answer 20

osmosis

Question 21

the force required to prevent the movement of water across a selectively permeable membrane.

Answer 21

Osmotic pressure

Question 22

can be measured by placing a solution into a tube that is closed at one end by a selectively permeable membrane and immersing the tube in distilled water.

Answer 22

Osmotic pressure

Question 23

solution has a lower concentration of solutes and a higher concentration of water relative to the cytoplasm of the cell.

Answer 23

hypotonic

Question 24

If the cell swells enough, it can rupture, a process

Answer 24

lysis

Question 25

solution, the concentrations of various solutes and water are the same on both sides of the cell membrane. The cell therefore neither shrinks nor swells

Answer 25

isotonic

Question 26

solution has a higher concentration of solutes and a lower concentration of water relative to the cytoplasm of the cell.

Answer 26

hypertonic

Question 27

When a cell is immersed in a hypertonic solution, water moves by osmosis from the cell into the hypertonic solution, resulting in cell shrinkage

Answer 27

creation

Question 28

a mediated transport process, involving membrane proteins such as channels or carrier proteins, to move substance across the cell membrane.

Answer 28

Facilitated diffusion

Question 29

necessary due to the selectively permeable nature of the membrane.

Answer 29

Facilitated diffusion

Question 30

consist of large protein molecules that extend from one surface of cell membranes to the other

Answer 30

Cell membrane channels

Question 31

constantly allow ions to pass through

Answer 31

Leak channels

Question 32

limit the movement of ions across the membrane by opening and closing

Answer 32

Gated channels

Question 33

which are proteins within the cell mem-brane, are also involved in facilitated diffusion. Can move water-soluble molecules or electrically charged ions across the cell membrane,

Answer 33

Carrier molecules

Question 34

a process that utilizes membrane proteins to move substances across the cell membrane from regions of lower concentration to those of higher concentration, against a concentration gradient

Answer 34

Active transport

Question 35

a genetic disorder that affects the active transport of CI- into cells.

Answer 35

Cystic fibrosis

Question 36

involves the active transport of one substance, such as Na*, across the cell membrane, establishing a concentration gradient, which then provides the energy for moving a second substances across the membrane.

Answer 36

Secondary active transport

Question 37

a genetic disorder that occurs at a rate of approximately I per 2000 births and currently affects 33,000 people in the United States.

Answer 37

Cystic fibrosis

Question 38

the diffusing substance moves in the same direction as the transported substance

Answer 38

cotransport

Question 39

the diffusing substance moves in the same direction as the transported substance

Answer 39

cotransport

Question 40

the diffusing substance moves in a direction opposite to that of the transported substance

Answer 40

countertransport

Question 41

Large water-soluble molecules that cannot be transported by carrier molecules, small pieces of matter, and even whole cells can be transported across cell membranes in membrane-bound sack

Answer 41

vesicles

Question 42

the uptake of material through the cell membrane by the formation of a vesicle

Answer 42

Endocrtosis

Question 43

often used for endocylosis when solid particles are ingested.

Answer 43

phagocytosis

Question 44

distinguished from phagocytosis in that much smaller vesicles are formed, and they contain liquid rather than solid particles.

Answer 44

Pinocytosis

Question 45

the release of substances from the cell through the fusion of a vesicle with the cell membrane

Answer 45

Exocytosis

Question 46

results in the uptake of materials by cells, and exocytosis allows for the release of materials from cells.

Answer 46

Endocytosis

Question 47

endothelial cells of blood capillaries, material is moved through the cell by

Answer 47

transcytosis.

Question 48

a large organelle within the cell

Answer 48

The nucleus

Question 49

The contents of the nucleus is separated from the rest of the cytoplasm

Answer 49

nuclear envelope

Question 50

during most of a cell's life, the chromosomes are loosely coiled and collectively

Answer 50

chromatin

Question 51

are diffuse bodies with no surrounding membrane that are found within the nucleus

Answer 51

nucleoli

Question 52

are the organelles where proteins are produced. May be attached to other organelles, such as the endo-plasmic reticulum.

Answer 52

Ribosomes

Question 53

a series of membranes forming sacs and tubules that extends from the outer nuclear membrane into the cytoplasm

Answer 53

The endoplasmic reticulum

Question 54

ER with attached ribosomes. A large amount of rough ER in a cell indicates that it is synthesizing large amounts of protein for export from the cell.

Answer 54

rough er

Question 55

ER without attached ribosomes. A site for lipid synthesis and participates in detoxification of chemicals within cells. In skeletal muscle cells, the smooth ER stores calcium ions.

Answer 55

smooth er

Question 56

consists of closely packed stacks of curved, membrane-bound sacs. It collects, modifies, packages, and distributes proteins and lipids manufactured by the ER.

Answer 56

Golgi apparatus

Question 57

caused by the inability of lysosomal enzymes to break down the carbohydrate glycogen produced in certain cells.

Answer 57

Pompe disease

Question 58

are membrane-bound vesicles formed from the Golgi apparatus. They contain a variety of enzymes that function as intracellular digestive systems.

Answer 58

Lysosomes

Question 59

are small, membrane-bound vesicles containing enzymes that break down fatty acids, amino acids, and hydrogen peroxide

Answer 59

Peroxisomes

Question 60

are small organelles with inner and outer membranes separated by a space

Answer 60

Mitochondria

Question 61

The outer membranes have a smooth contour, but the inner membranes have numerous folds

Answer 61

cristae

Question 62

The material within the inner membrane

Answer 62

mitochondrial matrix

Question 63

the main energy source for most chemical reactions within the cell.

Answer 63

ATP

Question 64

the internal framework of the cell.

Answer 64

The cytoskeleton

Question 65

hollow structures formed from protein subunits.

Answer 65

Microtubules.

Question 66

small fibrils formed from protein subunits that structurally support the cytoplasm, determining cell shape. Some of it are involved with cell movement.

Answer 66

Microfilaments

Question 67

fibrils formed from protein subunits that are smaller in diameter than microtubules but larger in diameter than microfilaments. They provide mechanical support to the cell.

Answer 67

Intermediate filaments

Question 68

A specific type of intermediate filament

Answer 68

keratin

Question 69

a specialized area of cytoplasm close to the nucleus where microtubule formation occurs.

Answer 69

The centrosome

Question 70

are cylindrical structures that extend from the cell. are composed of micro-tubules, organized in a pattern similar to that of centrioles, which are enclosed by the cell membrane. are numerous on surface cells that line the respiratory tract.

Answer 70

cilia

Question 71

have a structure similar to that of cilia but are much longer, and they usually occur only one per cell.

Answer 71

flagella

Question 72

are specialized extensions of the cell membrane

Answer 72

Microvilli

Question 73

the process by which information stored in the genes of DNA molecules directs the manufacture of the various proteins of our cells.

Answer 73

gene expression

Question 74

the first step in gene expression and it takes place in the nucleus of the cell.

Answer 74

Transcription

Question 75

There is one type of tRNA for each mRNA codon. In each tRNA there is a three-nucleotide sequence

Answer 75

anticodon

Question 76

The cell cycle includes two major phases: a nondividing phase.

Answer 76

interphase

Question 77

The cell cycle includes two major phases: a nondividing phase.

Answer 77

interphase

Question 78

the formation of daughter cells from a single parent cell.

Answer 78

Cell division

Question 79

Each of our body cells, except for reproductive cells

Answer 79

diploid

Question 80

The remaining 22 pairs of chromosomes

Answer 80

autosomes

Question 81

Most cells of the body, except those that give rise to reproductive cells

Answer 81

mitosis

Question 82

Each chromosome is composed of two genetically identical strands of chromatin

Answer 82

chromatids

Question 83

linked by a specialized region

Answer 83

centromere

Question 84

the chromatin condenses to form visible chromosomes each composed of the two chromatids as described above. Also during prophase, microtubules called spindle fibers extend from the centrioles. Some of these spindle fibers attach to the centromeres of each chromosome. The centrioles divide and migrate to each pole of the cell. In late prophase, the nucleolus and nuclear envelope disappear.

Answer 84

prophase

Question 85

the chromosomes align near the center of the cell. The movement of the chromosomes is regulated by the attached spindle fibers.

Answer 85

metaphase

Question 86

the chromatids sepa-rate. When this happens, each chromatid is then called a chro-mosome. At this point, two identical sets of 46 chromosomes are present in the cell. Each of the two sets of 46 chromosomes is moved by the spindle filers toward the centriole at one of the poles of the cell. Each set of chromosomes has reached an opposite pole of the cell, and the cytoplasm begins to divide.

Answer 86

anaphase

Question 87

the chromosomes in each of the daughter cells become organized to form two separate nuclei, one in each newly formed daughter cell. The chromosomes begin to unravel and resemble the genetic material during interphase.

Answer 87

telophase

Question 88

The process by which cells develop with specialized structures and functions

Answer 88

differentiation