Chapter 3 - The Cellular Level of Organization - Part 2

Question 1

Phases of interphase

Answer 1

G0 phase — specialized cell functions only
G1 phase — cell grows, duplicates organelles
S(ynthesis) phase — DNA replication
G2 phase — finishes proteins necessary to undergo mitosis and centriole replication

Question 2

Prophase

Answer 2

1. Chromatin condenses into chromosomes 2. Nuclear envelope disappears 3. Centriole pairs move to cell poles and form the mitotic spindles to separate DNA

Question 3

Metaphase

Answer 3

Chromosomes align in a central plane

Question 4

Anaphase

Answer 4

Microtubules pull chromosomes apart

Question 5

Telophase

Answer 5

1. Nuclear membranes re-form 2. Chromosomes decondense 3. Spindle apparatus is dismantled

Question 6

When does cytokinesis begin?

Answer 6

Occurs during telophase, marked by the appearance of the cleavage furrow, but is actually a separate process

Question 7

Purpose of mitosis

Answer 7

Growth and repair

Question 8

Passive transport

Answer 8

Move ions of molecules across the plasma membrane with no expenditure of energy by the cell

Question 9

Active transport

Answer 9

Requires that the cell expend energy, generally in the form of ATP

Question 10

Diffusion

Answer 10

Net movement of a substance from an area of higher concentration to an area of lower concentration

Question 11

Selectively permeable

Answer 11

Permits the free passage of some materials and restricts the passage of others

Question 12

Concentration gradient

Answer 12

Difference between the high and low concentrations of a substance

Question 13

Five factors which influence diffusion rates

Answer 13

Distance, molecule size, temperature, concentration gradient, and electical forces

Question 14

Simple diffusion

Answer 14

Materials (lipid-soluble and dissolved gases) diffuse directly through plasma membrane

Question 15

Channel-mediated diffusion

Answer 15

A concentration gradient drives movement of solute through a transmembrane channel protein

Question 16

Osmosis

Answer 16

Diffusion of water across the cell membrane

Question 17

Hydrostatic pressure

Answer 17

Fluid pressure

Question 18

Osmolarity

Answer 18

Osmotic concentration; the total solute concentration in an aqueous solution

Question 19

Isotonic

Answer 19

A solution that does not cause an osmotic flow into or out of a cell

Question 20

Hypotonic

Answer 20

In comparing two solutions, the solution with the lower osmolarity; fewer solutes; loses water through osmosis

Question 21

Hypertonic

Answer 21

In comparing two solutions, the solution with the higher osmolarity; more solutes; gains water through osmosis

Question 22

Hemolysis

Answer 22

Cell ruptures

Question 23

Crenation

Answer 23

The shrinking of red blood cells ina hypertonic solution

Question 24

Carrier-mediated transport

Answer 24

Integral proteins bind specific ions or organic substrates and carry them across the plasma membrane

Question 25

Cotransport

Answer 25

Carrier protein transports two substances in the same direction simultaneously, either into or out of the cell - passive transport

Question 26

Countertransport

Answer 26

One substance moves into the cell and other other moves out - passive transport

Question 27

Facilitated diffusion

Answer 27

Carrier proteins transport substance too large to fit through membrane channels - passive transport

Question 28

Sodium-potassium ATPase

Answer 28

Carrier protein involved in sodium-potassium exchange process - active transport

Question 29

Secondary active transport

Answer 29

The transport mechanism itself does not require energy from ATP, but the cell often needs to expend ATP at a later time to preserve homeostasis

Question 30

Vesicular transport

Answer 30

Materials move into or out of the cell in vesicles - active transport

Question 31

Endocytosis

Answer 31

Extracellular materials are packaged in vesicles at the cell surface and imported into the cell - active transport

Question 32

Phagocytosis

Answer 32

Vesciles form at the plasma membrane to bring solid particles into the cell - active transport

Question 33

Exocytosis

Answer 33

Intracellular cesicles fuse with the plasma membrane to release fluids and/or solids from the cells - active transport

Question 34

Resting membrane potential

Answer 34

Membrane potential in an undistrubed cell; between -10mV and -100mV in humans

Question 35

Interphase

Answer 35

The nondividing period

Question 36

Mitosis

Answer 36

Division of the nucleus

Question 37

Cytokinesis

Answer 37

Division of cytoplasm

Question 38

Cell division

Answer 38

A form of cellular reproduction where a single cell divides to produce a pair of daughter cells

Question 39

Daughter cells

Answer 39

Genetically identical cells produced by somatic cell division

Question 40

Apoptosis

Answer 40

Genetically controlled death of cells

Question 41

Meiosis

Answer 41

Production of sperm and oocyte

Question 42

DNA polymerase

Answer 42

Promotes bonding between the nitrogenous bases of the DNA strand and complementary DNA nucleotides dissolved in the nucleoplasm

Question 43

Leading strand

Answer 43

The upper leding strand where DNA polymerase adds nucleotides to make a single, continuous complementary copy

Question 44

Lagging strand

Answer 44

The lower lagging strand where the DNA polymerase works from left to right, adding nucleotides in sections

Question 45

Replication fork

Answer 45

Place where helicase enzymes unwind the strands of the template DNA and disrupt the hydrogen bonds between the bases

Question 46

Tumor

Answer 46

Mass or swelling produced by abnormal cell growth and division

Question 47

Metastasis

Answer 47

Dispersion of malignant tumor cells

Question 48

Cancer

Answer 48

Illness that results from the abnormal proliferation of any of the cells in the body

Question 49

Malignant tumor

Answer 49

Cells that no longer respond to normal growth controls

Question 50

Benign tumor

Answer 50

Cells where cell division and growth exceed the rate of cell death, but are contained within the epithelium or a connective tissue capsule

Question 51

DNA ligase

Answer 51

Enzymes which splice together the two DNA segments of the lagging strand

Question 52

DNA helicase

Answer 52

Enzyme that splits open the replication fork by unwiding the DNA strands and disrupting the hydrogen bonds

Question 53

Metaphase plate

Answer 53

Middle of the cell

Question 54

Diploid

Answer 54

Two complete sets - ie, two sets of 23 chromosomes

Question 55

Haploid

Answer 55

One set - ie, 23 chromosomes in sperm and oocytes