Unit III "Disease & Immunity"

Question 1

structure of a virus

Answer 1

nucleic acid wrapped in a protein coat

Question 2

lytic cycle

Answer 2

once phages enter the cell, the bacterium breaks open

Question 3

lysogenic cycle

Answer 3

viral DNA replication occurs without phage production or death of the cell

Question 4

cocci

Answer 4

spherical prokaryotic cells

Question 5

bacili

Answer 5

rod shaped cells

Question 6

binary fission

Answer 6

cells copy their DNA almost continuously and divide again and again

Question 7

endospore

Answer 7

protective cell produced within the prokaryotic cell when cell is exposed to unfavorable conditions

Question 8

what are the three domains of life?

Answer 8

bacteria, archaea, eukarya

Question 9

pathogens

Answer 9

disease causing organisms and bacteria

Question 10

exotoxin

Answer 10

proteins that bacterial cells secrete into their environment

Question 11

endotoxins

Answer 11

chemical components of the outer membrane of certain bacteria

Question 12

symbiosis

Answer 12

close association between organisms of two or more species

Question 13

endosymbiosis

Answer 13

one species living inside another host species

Question 14

immune system

Answer 14

body’s system of defenses against infectious disease

Question 15

phagocytic cells

Answer 15

engulf foreign cells or molecules and debris from dead cells

Question 16

natural killer cells

Answer 16

recognize virus-infected or cancerous body cells. when in contact, NK release chemicals that kill the diseased cells

Question 17

interferons

Answer 17

bind to plasma membrane receptors of uninfected proteins, stimulates them to build proteins that inhibit viral reproduction

Question 18

complement proteins

Answer 18

attack pathogens directly, coat surfaces of microbes, making the, easier for phagocytic to engulf

Question 19

histamine

Answer 19

causes blood vessels to dilate and leak fluid into the wounded tissue (causes swelling)

Question 20

lymphocytes

Answer 20

white blood cells that recognize and respond to specific invading pathogens

Question 21

B cells

Answer 21

lymphocytes that continue maturing in the bone marrow

Question 22

T cells

Answer 22

lymphocytes that migrate to the thymus

Question 23

antigen

Answer 23

molecule that elicited a response from a lymphocyte

Question 24

what are the functions of B cells and T cells?

Answer 24

recognize a single specific type of antigen and mount an immune response against it

Question 25

antibody

Answer 25

marks an antigen by combining with it to dorm an antigen-antibody complex

Question 26

effector cells

Answer 26

secrete huge amounts of antibodies into the blood and lymph

Question 27

primary immune response

Answer 27

antibodies produced by effector B cells reach their peak levels about two weeks after first exposure

Question 28

memory cells

Answer 28

long-lived cells that respond to subsequent exposures to the antigen by giving rise to effector cells and more memory cells

Question 29

secondary immune response

Answer 29

memory cells that find to the antigen intimate a faster and stronger response

Question 30

vaccine

Answer 30

harmless version of a disease-causing microbe; stimulates immune system to mount defenses against antigens

Question 31

humoral immune response

Answer 31

secretion of antibodies into the blood and lymph by B cells

Question 32

cell mediated immune response

Answer 32

effector T cells respond directly to antigens and have already entered body cells

Question 33

helper T cells

Answer 33

bind to other white blood cells that have previously encountered a pathogen

Question 34

what is the function of helper T cells?

Answer 34

stimulate the activity of cytotoxic T cells and help activate B cells

Question 35

cytotoxic T cells

Answer 35

only T cells that kill infected cells; death by lysis

Question 36

allergies

Answer 36

exaggerated sensitivities to otherwise harmless antigens in the environment

Question 37

lymph nodes

Answer 37

round organs packed with white blood cells