topic 6

Question 1

What are the two responses involved in specific immunity?

Answer 1

humeral response and cell mediated response

Question 2

what is the specific immune response?

Answer 2

an antigen specific response

Question 3

what do cytokines do in the humoral response?

Answer 3

activate B cells that the differentiate into either memory B cells of plasma cells

Question 4

what do plasma cells do?

Answer 4

make antibodies

Question 5

what do memory cells do?

Answer 5

give immunity by remembering the pathogen

Question 6

how do antibodies help clear infection?

Answer 6

agglutinating pathogens, neutralising toxins and preventing the pathogen from binding to the human cells

Question 6

what do cytokines do in the cell mediated response?

Answer 6

activate T cells which then differentiate into 3 types of cells.

Question 7

what are the 3 cells T cells differentiate into?

Answer 7

killer T cells, helper T cells and memory cells

Question 8

what do killer T cells do?

Answer 8

they bind to the infected body cell and produce perforin which causes cell lysis

Question 9

what do helper T cells do?

Answer 9

release substances e.g. cytokines that help activate B cells, t killer cells and macrophages

Question 10

what is splicing?

Answer 10

the process where introns are removed from pre- mRNA

Question 11

what is alternative splicing?

Answer 11

when certain exons are removed, as well as the introns, to form different mRNA strands\

Question 12

what does alternative splicing mean can happen?

Answer 12

more then one amino acid sequence and so more then one protein can be produced from one gene.

Question 13

what is an intron?

Answer 13

section of genes that don’t code for amino acids

Question 14

what is an exon?

Answer 14

the sections of genes that do code for amino acids

Question 15

what is pre-mRNA?

Answer 15

mRNA strands that contain both introns and exons

Question 16

name barriers to infection

Answer 16

skin, stomach acid, lysozyme, gut and skin flora.

Question 17

what triggers an immune response

Answer 17

foreign antigens

Question 18

three steps of the non-specific immune response

Answer 18

inflammation, production of interferons, phagocytosis

Question 19

what happens during inflammation

Answer 19

the immune system will recognise foreign antigens, causing the release of molecules that cause vasodilation around the site of infection, increasing blood flow.

Question 20

what do interferons do

Answer 20

they prevent the spread of viruses to other uninfected areas by: preventing replication, activating the specific immune system.

Question 21

what happens during phagocytosis

Answer 21

a phagocyte recognises the antigens on a pathogen, the cytoplasm moves around it to engulf the pathogen. the pathogen is then contained in a phagocytic vacuole, a lysosome will break down the pathogen using enzymes.

Question 22

what decomposes organic matter

Answer 22

microorganisms- bacteria, the secrete enzymes that decompose the dead organic matter

Question 23

how can scientists predict the time of death of a body

Answer 23

body temp, muscle contraction, forensic entomology, extent of decomposition, stage of succession

Question 24

body temp on time of death(TOD)

Answer 24

after death the metabolic reaction slow down and eventually stop, causing body temp to fall until it equals its surroundings- algor mortis

Question 25

muscle contraction on TOD

Answer 25

4-6 hrs after death, muscles start to contract and become stiff- rigor mortis. it happens due to the deprivation of oxygen, causing anaerobic respiration leading to a build up of lactic acid, inhibiting the production of ATP leading to stiffness.

Question 26

forensic entomology on TOD

Answer 26

after death the body is colonise day insects, the type of insect and their life stage can be used to determine how long the body has been there.

Question 27

extent of decomposition on TOD

Answer 27

immediately after death bacteria and enzymes start to decompose bodies, the extent of this decomposition can give an estimated time of death.

Question 28

the production of what give you immunity

Answer 28

memory cells

Question 29

what is active immunity

Answer 29

the type of immunity you get when your immune system makes its own antibodies

Question 30

what is passive immunity

Answer 30

type of immunity you get from being given antibodies made by a different organism

Question 31

what are the two types of active ad passive immunity

Answer 31

natural and artificial

Question 32

what is an antibiotic

Answer 32

chemicals that kill or inhibit the growth of microorganisms

Question 33

what do bactericidal antibiotics do

Answer 33

kill bacteria

Question 34

what do bacteriostatic antibiotics do

Answer 34

prevent bacteria from growing

Question 35

how do antibiotics work

Answer 35

they inhibit bacterial metabolism

Question 36

what is a hospital acquired infection

Answer 36

infections that are caught while a patient is being treated in hospital

Question 37

why are hospital acquired infections common

Answer 37

many people with weakened immune systems, around its of ill people

Question 38

what do hospitals do to prevent HAIs

Answer 38

handwashing stations, equipment and surfaces should be disinfected, isolation ward, wash bedding.

Question 39

why are antibiotic resistant HAIs more common in hospitals

Answer 39

more antibiotics being used within the hospital, bacteria in hospitals are more likely to have evolved resistant to them

Question 40

what are the prevention methods for bacteria resistant HAIs

Answer 40

antibiotics shouldn't be prescribed for minor bacteria infections, viral infections, to prevent infections. rotate the antibiotics being used.

Question 41

what is a DNA profile

Answer 41

genetic fingerprint of an organisms DNA

Question 42

what is the first step of DNA profiling

Answer 42

DNA sample obtained

Question 43

what is the second step of DNA profiling

Answer 43

PCR is used to amplify the DNA

Question 44

what is the third step of DNA profiling

Answer 44

a fluorescent tag is added, this makes the DNA visible under a UV light

Question 45

what is the fourth step of DNA profiling

Answer 45

gel electrophoresis is used to separate the DNA, according to length

Question 46

what is the fifth step of DNA profiling

Answer 46

the gel is viewed under a UV light, allowing comparisons to made between bands

Question 47

describe the PCR process

Answer 47

1. a mixture containing DNA, free nucleotides, primers and DNA polymerase, is heated to 95 breaking the hydrogen bonds 2. the mixture is cooled to 55 meaning primers bind to the strands 3.the mixture is heated to 75 allowing DNA polymerase to help form new copies of the DNA

Question 48

how can DNA profiling be used

Answer 48

forensic science, determine genetic relations, in animals and plants