the cell

Question 1

cell theory

Answer 1

all living things are composed of cells, the cell is basic functional unit of life, cell only arise from existing cells

Question 2

nucleus

Answer 2

contains all genetic material needed for replication of the cell, surrounded by nuclear envelope; nuclear pores allow for selective exchange

Question 3

nucleolus

Answer 3

subsection of nucleus where ribosomal RNA is synthesized

Question 4

mitochondria

Answer 4

contain outer membrane, which serves as a barrier, and an inner membrane with many infolds (christae) to increase surface area for ETC; intermembrane space=between the 2 membranes; matrix= inside inner membrane; capable of inducing cell apoptosis

Question 5

lysosomes

Answer 5

contain hydrolytic enzymes that can break down cellular waste or endocytosed products; contain these enzymes in an organelle to prevent cell damage

Question 6

smooth ER

Answer 6

lipid synthesis and detoxification of drugs and poisons; transports proteins from RER to golgi in vesicles

Question 7

golgi

Answer 7

modifies and sorts cellular products, then sends them off to correct location inside the cell

Question 8

peroxisomes

Answer 8

contain hydrogen peroxide to break down long fatty acid chains; synthesize phospholipids

Question 9

cytoskeleton

Answer 9

provides structure to the cell and serves as conduit for transporting materials around cell; composed of microfilaments, microtubules, and intermediate filaments

Question 10

microfilaments

Answer 10

made up of actin rods, which can allow for movement in cell; involved in division of cell materials during cytokinesis

Question 11

microtubules

Answer 11

polymers of tubulin; provide pathways on which motor proteins (kinesin, dynein) can move

Question 12

cilia

Answer 12

projections from a cell involved with movement of materials along the cell surface; ex. cilia line the respiratory tract

Question 13

flagella

Answer 13

involved with movement of the cell itself, such as movement of sperm cells

Question 14

9+2 structure

Answer 14

found in flagella and cilia or eukaryotic organelles involved with motility; 9 pairs of microtubules in outer ring and 2 microtubules in center

Question 15

epithelial tissue

Answer 15

covers the body and lines its cavities; tightly joined to each other and to the basement membrane, which lies underneath; makes up the parenchyma/the functional parts of most organs

Question 16

connective tissue

Answer 16

supports the body, provides framework for epithelial cells to carry out their function; main contributors to the stroma (support structure); produce collagen and elastin to form extracellular matrix; ex. bone, cartilage, tendons, ligaments, blood

Question 17

nucleoid region

Answer 17

area of prokaryotic cells where the single circular molecule of DNA is located

Question 18

archaea

Answer 18

single-celled prokaryotes, that contain some similarities to eukaryotes regarding their genes and metabolic pathways; resistant to many antibiotics

Question 19

bacteria

Answer 19

prokaryotic cells; some are mutualistic symbiotes- and provide benefits to humans, while others are parasites

Question 20

cocci

Answer 20

spherical bacteria

Question 21

bacilli

Answer 21

rod-shaped bacteria

Question 22

spirilli

Answer 22

spiral-shaped bacteria

Question 23

obligate aerobes

Answer 23

bacteria that require oxygen for metabolism

Question 24

anaerobes

Answer 24

bacteria that use type of metabolism that doesn’t require oxygen such as fermentation; obligate anaerobes die in presence of O2, facultative anaerobes can use O2 for respiration if present, and aerotolerant anaerobes aren’t harmed but can’t use it

Question 25

prokaryotic cells

Answer 25

single celled-each cell must perform all functions needed for life; has cell wall to protect itself, which can be gram negative or positive; cell membrane is used for electron transport chain in aerobes; have ribosomes, but subunits are different sizes than eukaryotes

Question 26

gram positive bacteria

Answer 26

cell wall has thick layer of peptidoglycan, which absorbs violet stain; also has lipoteichoic acid

Question 27

gram negative bacteria

Answer 27

cell walls are thin, contain much smaller amounts of peptidoglycan, which doesn’t absorb purple stain, so appears pink-red from safranin counterstain; outer membrane has lipopolysaccharides

Question 28

binary fission

Answer 28

asexual reproduction in prokaryotes; circular chromosome replicates and cell grows in size; plasma membrane and cell wall grow inward at midline to produce two identical daughter cells

Question 29

plasmids

Answer 29

source of extragenomic DNA in bacteria that may carry beneficial genes such as antibiotic resistance or virulence factors, which increase how pathogenic the bacteria is

Question 30

transformation

Answer 30

integration of foreign genetic material from the environment into host genome; usually comes from other bacteria which lysed

Question 31

conjugation

Answer 31

bacterial form of mating/sexual reproduction; two cells form conjugation bridge that allows transfer of genetic material; transfer from donor male (+) to recipient female (-); bridge made from sex pili found on male; male must have sex factor, F (fertility) factor to make pilus; during conjugation, F+ cell will replicate and donate F factor so donor will become F+

Question 32

transduction

Answer 32

genetic recombination that requires a viral vector (virus that carries genetic info from one bacteria to another)

Question 33

transposons

Answer 33

genetic elements capable of inserting and removing themselves from the genome; if inserted into coding region, may disrupt gene

Question 34

bacterial growth curve

Answer 34

Starts with lag phase, bacteria adapts to new environment, no growth; then exponential phase: huge reproduction and increase in number of bacteria; then stationary phase because resources reduced from huge growth; last death phase: depletion of resources, so large reduction, most bacteria die

Question 35

Viruses

Answer 35

not living, because acellular!; has protein coat (capsid), and genetic material, but requires host cell to replicate and express genetic info; viral progeny produced by host is called virions

Question 36

bacteriophages

Answer 36

viruses that specifically target bacteria; they inject genetic material, while protein shell doesn’t enter cell; has tail sheath which acts like a syringe and tail fibers which help recognize the host cell and bind

Question 37

Positive sense RNA virus

Answer 37

genome may be directly translated to functional proteins by ribosomes of host cell

Question 38

Negative sense RNA virus

Answer 38

require synthesis of rna strand complementary to negative sense strand, which is then used for protein synthesis in host cell

Question 39

retrovirus

Answer 39

contain reverse transcriptase, to synthesis DNA from RNA, which is then integrated into host genome

Question 40

lytic cycle

Answer 40

bacteriophage replicates and makes lots of virions; once cell is swollen with virions, cell lyses and other bacteria can be infected

Question 41

lysogenic cycle

Answer 41

virus replicated as the bacterium reproduces because it is integrated into host genome; at some point environmental factors may cause virus to leave genome and revert to lytic cycle

Question 42

prions

Answer 42

infectious particles that cause disease by triggering misfolding of other proteins

Question 43

viroids

Answer 43

small pathogens consisting of short, circular single-stranded RNA that infect plants; can bind to RNA sequences and silence genes in plant genome