module 4 and 6 Flashcards

Question

agammaglobulinemia results in a lack of mature B lymphocytes in a person's blood
suggest and explain one symptom of agammaglobulinemia

Answer 1

weaker immune system - greater susceptiility to infection
fewer B lymphocytes = fewer antibodies, plasma cells

Answer 2

allele codes for transcription factor or repressor protein that inhibits the transcription of the other allele

Answer 3

less than 5% probability that different is due to chance

Answer 4

circumference - CONTINUOUS
cause of feature: genetics + environment
no of genes invovled: many, polygenic
type of graph used to present data: line graph

seed-containing/ seedless - discontinuous
cause of feature: genetics
no of genes invovled: one or two
type of graph used to present data: histogram

Answer 5

antibiotic = selective pressure
variation; some bacteria have reistance
bacteria with resistance have selective advantage, able to survive + reproduce
resistant population develops, higher proportion of resistant bacteria
antibiotive becomes ineffective

Answer 6

genetic polymorphism
proportion of heterozygotes

Answer 7

population drops - many alleles lost
modern population descended from few survivors
inbreeding

Answer 8

small population:

more likely that alleles are lost from population
population more vulnerable to environmental change
one allele has a proportionally higher effect on small population

Answer 9

genetic variation is PRE-EXISTING

mutations
sexual reproduction
random fertilisation
crossing over, independent assortment in meiosis

diffrential survival

finches with extreme beak sizes are less likely to survive. Too small/too big are selected against.
survivors have alleles for avg. beak size - alleles for avg. beak more likely to be inherited by offspring
increase in allele frequency for avg. beak size over time

Answer 10

different selection pressure / enviornment.
geographical isolation, reproductively seperated, no gene flow between seperated population
random mutation
survive / reproduce
beneficial alleles passed on
frequency of advantageous alleles
directional selection
changes in alleles of population will affect phenotype and over time, diverge and form seperate species

Answer 11

different selection pressures/environment
genetically isolated (reproductively isolated)
mutation
time (happens over many generations)
directional selection

Answer 12

DNA is universal - in all organisms
compare DNA between species
similar base sequence = recent common ancestor

Answer 13

working out the DNA base sequence

Answer 14

next generation sequencing

high throughput sequencing
(vs. sanger/chain termination)

Answer 15

work out base sequence
base sequence codes for amino acid sequence
specifically, each triplet codes for one amino acid (DNA is a triplet code)

Answer 16

Bioinformatics

DNA is universal!
database of data- facilitates access to large amount of data on DNA and proteins
allows us to identify vulnerable populations - so that vaccination programmes can target certain indivduals

DNA sequencing

sequence DNA of virus
predict amino acid sequence of its viral antigen (protein)
allows us to manufacture vaccines with the correct antigen

Answer 17

database of data - facilitates access to large amounts of data on proteins, DNA
computer analysis - rapid compairson of sequences with newly sequenced allele

comuputer modelling of new protein structure from base sequence (base sequence - predict protein structure!)

Answer 18

1. idea of inbreeding due to artifical selection

inbreeding, more homozygous recessive alleles
inbreeding depression - greater chance of recessive alleles being expressed in phenotype

2. allele for genetic disease is linked to gene for desirable trait - inherited together!

Answer 19

use bioinformatics to link the genes with the genetic disease
compare genomes of dog breeds
identify base sequences that are only present in dogs with the genetic condition. we can identify dogs carrying the CPF allele
link DNA in genes to specific proteins

Answer 20

memory cells reduced in number
booster produces more memory cells to improve immunity

Answer 21

genome is very similar between humans
just using coding sequences would NOT provide unique profiles
non coding DNA - contains variable numbers of short tandem repeats

Answer 22

doesnt denature at 95 degrees during DNA strand seperation
so PCR can be cycled repeatedly without stopping to reload enzyme

Answer 23

fluorescent tag
UV light

Answer 24

a) heated to unfold protein (denature) - this exposes charges
b)

different proteins have different overall charges (variable r groups!)
binding of SDS makes all proteins negatively charged

This means that:

proteins are seperated by length (not by different charges)
proteins move in same direction

Answer 25

electrophoresis seperates charged particles vs. TLC seperates non-charged particles
buffer solution used for electrophoresis
fluorescent tag vs. dye

Answer 26

form of gene therapy

stops gene expression / silencing the effect of the faulty gene

base sequence unchanged
mRNA is inhibited - translation does not happen
gene not expressed

Answer 27

use marker gene
i.e. gene for fluoresence
examine under UV light

Answer 28

reverse transcriptase (enzyme) - makes complementary DNA, cDNA
builds double stranded DNA using DNA polymerase

Answer 29

marker gene
indicates which bacteria have taken up the plasmid

Answer 30

Somatic vs. germline

not permenant/short term
gene introduced into body cell (vs. gene introduced into gamete, embryo)
isnt' inherited

Answer 31

frameshift (bases read out of frame)
altered triplets

adjacent genes switched on/off by new gene (affects expression of other genes)
new gene could disable a functioning gene

Answer 32

primary metabolites essential for growth

i & ii - mainly primary metabolites

secondary metabolites have no rle in growth. formed during stationary phase.

iii & iv - mainly secondary metabolites

Answer 33

runners
suckers
stolons
tubers
rhizomes

[asexual reproduction]

Answer 34

remove cells from meristem tissue in root/shoot tips or axial buds
tissue sample removed is called the explant
ethanol used to sterilise plant tissue [aseptic technique]
hormones stimulate mitosis, which produces a mass of cells = callus

explant is grown into a new clone of original plant

contamination may cause the micropropagation to fail:

asepsis = less contamination = less competition for nutrients, space

Answer 35

micropropagation:

produces more clone offspring
needs more equipment
needs more skills, more expensive, labour intensive
more aseptic technique involved

Answer 36

some crops cannot reproduce sexually/from seed
quicker than growing from seed/sexual reproduction. process is rapid, yields large numbers of new plants.
not seasonal - plant cloning can be done at any time of year
predictable yield

Other advantages:

rare/endangered species saved from extinction
plants produced all have the same genotype and phenotype - plants can be genetically modified to be free of disease

Answer 37

cut shoot from healthy plant (ideally with no flowers + leaves removed - reduces water loss by transpiration, encourages root growth)
cut stem at a slant between nodes
dip in hormone rooting powder [roots develop]
place in moist compost
cover with plastic bag (prevents transpiration stress; provides moisture)

should be done with aseptic technique to stop contamination

Answer 38

tissue culture/micropropagation

many explants taken from original parent plant - to then be grown into clones
meristem from plantlets can be subdivided
calluses can be subdivided

idea of multiplication, using totipotent nature of plant cells.

Answer 39

Examples:
e.g. lactobacillus for yoghurt
e.g. fusarium for mycoprotein
e.g. yeast for bread, alcohol

1. low cost
nutrients for growth is cheap, readily available
can use waste materials

2. healthy alternative
e.g. mycoprotein has high protein, low cholesterol

3. large yield, high production
microorganisms reproduce quickly

4. can be produced in any location
growth not affected by climate, conditions are controlled

5. better for environment
less use of land, low energy requirements

Answer 40

dilute sample taken from colony
multiply result by dilution factor

Answer 41

aseptic technique- avoid contamination
incubate at suitable temp.
provide nutrients

Answer 42

could result in growth of human pathogens, harmful bacteria

Answer 43

reuseable-cost efficient
avoids need to seperate enzymes from products in downstream processing (downstream processing cost is reduced)
faster yield = more profit

Answer 44

entrapment - contain within partially permeable membrane

Answer 45

immobilised enzymes are less easily denatured

tertiary structure is supported by a membrane
part of the enzyme isn't fully exposed to the high pH

Answer 46

1. reduced need for downstream processing - product isn't contaminated with enzyme
2. immobilised enzymes are less easily denatured - wider temp. range - can be run at higher temp. - faster, yield is higher

Answer 47

1. fewer exposed active sites
2. active sites + substrates mix more slowly
3. high initial cost

Answer 48

penguin species have overlapping niches
effect of competition: competitive exclusion

population increases as resources readily available - e.g. food, space
no limiting factors
outcompetes adelie

population decreases as theres more competition from gentroo

Answer 49

disease
changes in climate affecting heather and red grouse populations
competition from new predator for red grouse
predation

Answer 50

1. local people invovled
(if preservation, people would not be there)
2. sustainable use/area used to logging, farming
(logging etc. not consistent with preservation)
3. measured to maintain biodiversity
(preservation would leave the park untouched)

Answer 51

idea that peat bogs are often already damaged and REQUIRE mamagement
vs. preservation = leaving ecosystem untouched, no human interference

Answer 52

cut trunk close to ground - leaves stump
new shoots grow from stump
protect shoots grom grazers
rotational coppicing: divide woodland into regions + coppice on rotation, repeat

Benefits:

new stems grow more rapidly than samplings
roots prevent soil erosion, maintains soil quality
fewer large trees - more light for smaller plants, more diversity and variety of habitats as light reaches ground

Answer 53

1. reduced mesh size so undersized fish can escape
monitoring is expensive, hard to enforce
2. fish quotas
false reporting of catches

other measures:
sanctions
days at sea
trawler size

other difficulties:
ocean area too large to monitor

Answer 54

bacteria - ring rot
virus - tobacco mosaic
fungus - black sigatoka
protocist - blight

Answer 55

bacteria - tubercolosis, meningitis
virus - HIV, flu
fungus - athletes foot, ringworm
protocist - malaria

Answer 56

plasmodium

Answer 57

droplet infection - wear masks
close contact- stay indoors, quarantine people with symptoms
measures to kill rats/fleas

Answer 58

cellulose cell wall
damage to cell wall by insects, vectors

Answer 59

1. aromatic compound - antibacterial
2. physical barrier - prevents pathogens entering would

Answer 60

many medicines are developed from traditional remedies
many plants produce molecules with medicinal benefits
many plants yet to be discovered

Answer 61

virus RNA recognised + destroyed
virus replication stops

breaking down RNA- breaks phosphodiester bonds

faulty RNA is destroyed - so that faulty proteins aren't made
prevents errors in protein synthesis

Answer 62

goblet cells produce mucus - traps pathogens
cilia waft mucus
- cytoskeleton/microtubules make up cilia

Answer 63

mosquito mouthpart pierces skin
pathogen injected directly into blood

Answer 64

binds to antigen on pathogen
assists binding to phagocyte
"enchances phagocytosis" - pathogen more easily engulfed and digested

Answer 65

specific receptors
multi lobed nucleus
lysosomes
well developed cytoskeleton

Answer 66

B cells have antigen receptors
activated B cells divide by mitosis - clonal selection and expansion
diffrentiate into plasma cells
secrete antibodies specific to antigen
--------------------------
T helper cells bind with B cell APC - stimulated - release cytokines
stimulate B cell proliferation/ clonal expansion

Answer 67

immunologically distinct
toxins will have different amino acid sequence, different 3D shape
toxin acts as antigen, immune response will be determined by shape of toxin!

immune system
B cells (with complementary receptors) bind to antigens- B cell APC
T helper cells bind to APCs - produce interleukins
B cells activated by T-helper cells
clonal expansion, selection
B cells diffrentiate - plasma cells - produce antibodies - neutralise toxin (anti-toxin)

Answer 68

Genes

animals inherit genes that code for immune cells e.g. lymphocytes, antibodies
different alleles code for different immune cells
genetic conditions

Environment

exposure to different pathogens - causes different immune responses - different memory cells
vaccinations produce primary immune responses - memory cells
environmental influences e.g. pollen hayfever
poor diet - e.g. low protein may result in fewer antibodies
autoimmune diseases with enviornmental trigger

Answer 69

memory cells not acting in initial exposure (primary response)

second exposure - memory cells remain in blood - faster response - faster clonal expansion, more antibodies produced

Answer 70

primary immune response - just after vaccination
primary response is delayed - slow antibody production, involves clonal expansion, clonal selection

secondary immune response - just after infection
secondary response much faster - more antibodies produced due to memory cells / faster clonal selection
immunological memory

Answer 71

disulfide bridge
holds polypeptide chains together (light chain + heavy chain)

Answer 72

abnormal immune repsonse against healthy tissues in body
immune system stops recognising self and non-self cells, attacking healthy body tissue

could be caused by T regulator cells working ineffectively

Answer 73

cause pathogens carrying antibody-antigen complexes to clump together
prevents them from spreading through the body
also enhances phagocytosis - easier for phagocytes to engulf agglutinated pathogens

Answer 74

artificial and passive immunity

injected - so its artificial
pt. not producing antibodies, not producing immune response

Note that as the pt's immune response isnt activted, there are no memory cells that can produce antibodies in a secondary response. reinfection requires another infusion of antibodies

Answer 75

produce immune response
antibodies produced
activation of lymphocytes
memory cells remain

Answer 76

signficant effect on ecosystem
many other species rely on the keystone species

Answer 77

dig hole + place container in ground
cover to protect from rain + predators
leave overnight
identify + count invertebrates
sample area randomly at 5+ sites

Answer 78

closer to 1 = higher biodiversity value = more stable

Answer 79

no of samples within each area should be proportional to size of area
sampling within each area should also be random

Answer 80

use same method to capture individuals - e.g. butterfly net
use same key to identify species
collect at different times of year
more transects in different parts of area 1 and 2

Answer 81

ecotourism
money from tourists - used to support conservation
e.g. planting trees, creating nature reserves, reintroduction programmes

Answer 82

many drugs originate from plants
so maintaining biodiversity increases the chance of developing/discovering new drugs
genetic resource for future, once a species is extinct, its gone forever. may be plants yet to be discovered that are useful

Answer 83

exhibit natural behaviour
less likely to catch disease from humans

poaching more likely
could be wiped out

Answer 84

Convention on international trade in endangered species

controls trade of endangered species

Answer 85

environmental (countryside) stewardship scheme

farmers offered payments for conservation
e.g. protect habitats, provide visitor opportunities, ensure land managed well etc.

Answer 86

Rio convention on Biological Diversity
international agreement

conservation
sustainable use of biological resources

countries signing convention also agreed to implement national strategies for the conservation and sustainble use of biodiversity.

Answer 87

same domain - both eukaroytes
different kingdoms - animal vs. plant - e.g. plants have cellulose cell walls

Answer 88

reproduce fertile offspring
genetically similar
similar phenotype

Answer 89

universally identified (vs. there are different common names for same organism)
tells us genus and species

Answer 90

eukaroytic cells (contain nucleus, membrane bound organelles)
mainly unicellular
autotrophic or heterotrophic

Answer 91

unicellular or multicellular
nucelus, membrane bound organelles (eukaryotic)
cell wall = chitin
no chloroplasts
store food as glycogen
saprophylic

Answer 92

mainly unicellular
eukaryotic- membrane bound organelles, nucleus etc.(som may have chloroplasts)
heterotrophic or autotrophic

Answer 93

nucleus
membrane bound organelles
80s ribosomes
DNA linear
DNA associated with histones

Answer 94

fossils
fossils deeper in ground = older than those near surface

Answer 95

an illness or disorder of the mind or body that leads to poor health

each disease is associated with a set of symptoms
communicable: caused by pathogens, transmissable - spread within a population between individuals

Answer 96

1. tubercolosis

bacteria infect lungs
causes chronic cough, bloody mucus
TB associated with poor sanitation

2. bacterial meningitis

N.meningitidis can cross the meninges to cause inflammation
symptoms: fever, headache

3. ring rot

bacteria infect vascular tissue
prevents transport of water - plant wilts, dies

Answer 97

1. TMV

yellowing of leaves

2. influenza

high temp, body aches, fatigue

3. HIV

retrovirus - reverse transcriptase - can make DNA from RNA
inserts DNA into host DNA, hijacks machinery to replicate viral proteins, own genetic material

Answer 98

1. malaria

protist = plasmodium
parasite = mosquitoes
fever, chills, fatigue

2. potato blight

protist = p.infestans
has fungal characteristics e.g. transmitted via spores

Answer 99

1. cattle ringworm
2. athletes foot

these are fungal diseases that exist on the surface of skin

3. black sigatoka

fungal disease in bananas
spreads through leaves - reduces ability to photosynthesise
leaves die

Answer 100

transfer of pathogens from an infected host to an uninfected host
during infective stages, pathogens produce a large no. of individuals to increase likelihood that some will find a new host, survive.

Answer 101

direct - from one host to another host
indirect - a vector that is unaffected by the pathogen transfers it to a new host

Answer 102

1. physical contact e.g. TMV leaves touch leaves of uninfected plant
2. close proximity - e.g. influenza viruses spread in air via droplets which can be breathed in
3. spores - dispersed by wind, water

Answer 103

transmitted by direct exchange of body fluids:

blood donation
sexual intercourse
sharing of needles
from mother to child (mixing of blood, through placenta)

Answer 104

infected people cough
mycobacterium tubercolosis bacteria enters air in droplets
uninfected people breathe in droplets

Answer 105

involves vectors
vector is any organism that transfers a pathogen from an infected individual to an uninfected individual
vector usually unaffected by pathogen
e.g. insects are ideal vectors as they reproduce in large numbers - increases likelhood of pathogen transmission

Answer 106

caused by protoctist plasmodium
transmitted to humans by an insect vector - female anopheles mosquito (feeds on human blood)

malaria also transmitted by blood transfusion, unsterile needles, mother to child across placenta

Answer 107

direct:

high population density / close proximity
e.g. large no. of crops in small area can lead to transmission of pathogens such as TMV ~ monoculture

indirect:

population of vectors influenced by climate, weather
common vectors include mosquitoes, aphids

Answer 108

anopheles mosquito favours habitats with high humidity, high temp, high rainfall
malaria found mostly throughout the tropics and sub-tropics

efforts to eradicate malaria were unsucessful:

plasmodium became resistant to drugs being used to control it
anopheles mosquitoes became resistant to insecticides

Answer 109

level of poverty e.g. waterborne diseases spread when human faecal matter contaminates drinking water, sanitation, overcrowding

overcrowding: accomodation with more space, more ventilation
poor sanitation: sewage disposal, handwashing antibacterial gels, greater public awareness
lack of trained healthcare proessionals - lack of vaccinations, treatments: better access to hospitals, locally educate

level of human migration - people can travel with diseasr and spread to wider area

quarantine, lockdown
restrict travel

behavioural, cultural practices -e.g. ill cared for by family - exposed to pathogen

care done by trained health professionals
protective clothing, gloves
better access to hospitals

Answer 110

passive defence mechanisms are always present:
e.g. physical barrier that prevent pathogens from entering
e.g. chemicals that prevent growth of pathogens

active defence mechanism activated when pathogens invade
e.g. formation of physical barriers by callose

Answer 111

physical barriers:

waxy cuticle [only way that viruses/bacteria can penetrate is if there is a wound on the leaf/stem surface. wounds are commonly caused by grazing herbivores]
cellulose cell wall
bark
casparian strip

chemical defences:

toxic compounds
sticky resin in bark - traps pathogens so they cant spread
enzyme inhibitors - tannins

Answer 112

activated once a pathogen has invaded

hypersensitivity - rapid death of tissue surrounding infection site [deprives pathogen of host tissue, nutrients]
physical barriers to reduce spread of pathogen - e.g stimulates release of callose, lignin - deposited between membrane & cell wall
narrowing of plasmodesmata - callose reduces size of plasmodesmata which connect neigbouring plant cells
blockage of phloem - sieve pores filled with callose - prevents phloem sap transport

Answer 113

e.g. molecules produced when cellulose breaks down, act as signals to cell surface receptors - stimulates release of defence chemicals, phytoalexins:

delay pathogen reproduction
disrupt pathogen meabolism
disrupt bacterial cell membranes
stimulate release of chitinases that break down chitin cell walls in fungi

Answer 114

1. skin- waterproof barrier, sweat glands
2. stomach acid
3. mucous membranes - mucus trap pathogens, macrophages
4. expulsive reflexes - sneezes, coughs, vomiting - expel pathogens

blood clotting:

cut breaches skin
blood clotting: soluble fibrinogen --> insoluble fibrin - forms mesh that traps platelets + blood cells
platelets release clotting factors e.g. thromoplastin
blood clot seals wound
clot dries out - forms scab, epidermal cells below scab grow

works to prevent excess blood loss & prevents entry of pathogens

inflammatory response:

redness, swelling of tissue, heat
mast cells activated, histamines, cytokines released:
histamines cause vasodilation - increased blood flow, redness, heat - raised temp. prevents pathogens reproducing
histamines cause vessel walls to be leaky - swelling
cytokines attract phagocytes

fevers

cytokines stimulate hypothalamus to increase temp
higher temp inhibits pathogen reproduction

Answer 115

phagocytes attracted by chemicals produced by pathogen + cytokines
phagocyte recognises pathogen as non-self
binds and engulfs
forms phagosome
phagosome fuses with lysosome to form a phagolysosome
enzymes from lysosome digest, break down pathogen
antigen processing - processed antigens combine with glycoproteins, MHC. MHC/antigen complex. APC

Answer 116

plasma cells are antibody-secreting
have extensive endoplasmic reticulum, many ribosomes, golgi

Answer 117

macrophage engulfs antigen by phagocytosis, antigen processing, antigen/protein complex, macrophage APC
helper T cell bind to specific antigen/MHC protein complex
triggers macrophage to release cytokines that activate helper T cell
activated helper T cell releases own cytokines
stimulates T cell rapid division by mitosis: cloned helper T cells, T memory cells, T killer cells, also produce cytokines that stimulate B cell division, phagocytosis

B cell receptor binds to antigen, engulfs antigen by endocytosis
Note B cell receptor = immunoglobulin = same structure as antibody
antigen processing, antigen/protein complex displayed on cell surface - B cell APC
helper t cell binds
triggers release of cytokines from T cell
stimulate B cell clonal expansion, selection
memory cells, plasma cells (which produce antibodies)

Answer 118

mature in thymus gland
helper T cells: CD4 receptors, bind to antigens on APCs, relasing interleukins that stimulate B cell activity, phagocytosis, production of more T cells
T killer cells - destroy body cells infected by pathogen
T memory cells - immunological memory, remain in blood for a long time
T regulator cells - supress immune system once a pathogen is eliminated. inhibits cytokines.

Answer 119

mature in bone marrow
plasma cells - circulate in blood, produce antibodies
B effector cells - divide to form plasma cell clones
B memory cell - remain in blood for a long time, immunological memory

Answer 120

Y-shaped glycoproteins, immunoglobulin
bind to specific antigens or toxins
four polypeptide chains - two heavy and two light chains
light and heavy chain held together by disulfide bridges

Three regions:

variable region gives antibody specificity, specific to shape of antigen
hinge region of antibody - antibody can bind to two antigens, one at each of its identical anitgen-binding sites
constant region - same in all antibodies, allows binding to receptors

Answer 121

opsonisation - enhance phagocytosis, antigen-antibody complex is easily engulfed by phagocytes
agglutination - pathogens carrying antigen-antibody complexes clump together - prevents spread through body + makes it easier for phagocytes to engulf agglutinated pathogens
anti-toxin - binds to toxins produced by pathogens, rendering them harmless
neutralisation - pathogen part of antigen-antibody complex - prevents pathogens from invading host cell

Answer 122

immune ststem stops recognising self cells, attacks healthy body tissue, abnormal immune response

type 1 diabetes - autoimmune destruction of B cells that secrete insulin
Treatment: immunosuppressant drugs, pancreas transplant, insulin injection

Rhemuatoid arthritis - affects joints
Treatment: immunosuppressants, anti-inflammatory drugs

Answer 123

induce artifical active immunity
specific immune response, antibodies released by plasma cells
two main types of vaccine - inactivated, live attentuated (weakened)
injection [vein/muslce] or oral
produce long term immunity due to formation of memory cells
vaccination programmes major part of public health e.g. UK babies vaccinated against polio, measles

Answer 124

arises when a sufficiently large proportion of population is vaccinated
this makes it difficult for a pathogen to spread
allows vulnerable people who cannot be immunised to be protected

Answer 125

people living or working near a vulnerable or infected person are vaccinated in order to prevent them from catching or transmitting the disease
individuals within the ring are protected

Answer 126

virus was stable and didn't mutate - hence vaccine was effective, global vaccine rollout easier
symptoms easily identifiable - suverillance therefore possible, easier to diagnose + trace
smallpox only spread by humans - easier to break transmission pathway

Answer 127

increasing antibiotic resistance, increasing need to discover/develop new drugs:

analyse organism genome to find candidate genes that may code for potential drugs
modify drugs that already exist
identifiy useful compounds produced by organisms
identifying molecules that fit into drug targets e.g. neurotransmitters, hormones, receptors

Answer 128

development of more targeted and personalised drugs
genomic medicine - information about an individual's genes used
in theory: most effective drugs can be prescribed for an individual based on their genome, reduced chance of side effects

another form of personalised medicine:

genetic screening: individuals more vulnerable to develop specific diseases identified, preventative measures taken

Answer 129

inhibit synthesis of bacterial cell wall
inhibit translation or transcription of bacterial DNA
affects cell surface membrane function

Answer 130

form of natural selection

bacteria evolve as they reproduce quickly, acquire random mutations

genetic diversity exists in population of bacteria - some have antibiotic resistance
antibiotic use exerts selection pressure: bacteria with antibiotic resistance have a selective advantage - more likely to survive, reproduce.
over several generations, the entire population is antibiotic- resistant

as well as passing on alleles for antibiotic resistance through reproduction, some bacteria confer resistance: plasmids with antibiotic resistant genes can be shared between bacteria of both the same and different species

~ horizontal gene trasnfer

Answer 131

Commonly prescribed antibiotics are becoming less effective
misuse, overuse

overuse of antibiotics when not necessary
large scale use of antibiotics in farming
pts not completing their full course of antibiotics prescribed by doctors

Answer 132

doctors avoiding overprescribing of antibiotics. only when needed. not used in non-serious infections
pts finishing the entire course of antibiotics prescribed
less use in agriculture e.g. used to cure rather than prevent (not prophylactic)

Answer 133

e.g. antibotic resistance gene for penicillin: penicillinase breaks down penicillin molecules, rendering harmless
resistance gene codes for enzyme that breaks down the antibiotic

e.g. antibiotic resistance gene for tetracycline: codes for protein pump that moves antibiotic from cell
resistance genes codes for protein pump that moves antibiotic out from cell

Answer 134

classification is based on phylogeny
statocysts could have evolved on more than one occasion
could be example of convergent evolution

Answer 135

crossbreed high-yielding wheat plants
asess/measure the yield
crossbreed the high-yielding offspring
over generations

Answer 136

use of fertiliser
use of pesticides, incesticides
better harvesting technology, tractors

Answer 137

genetic drift

Answer 138

C:

greatest change in allele frequency
SMALL POPULATION - thus:

each random mating more significant
each individual forms a greater proportion of gene pool
easier to lose allele from gene pool
more subject to founder effect

Answer 139

Autosomal linkage

alleles are linked on same chromosome
linked alleles inherited together
Ry and rY on chromosomes in heterozygotes
genes close together

Answer 140

udder size --> milk production

Answer 141

artificial selection!

selection of desired feature e.g. udder size/milk production - assess which individuals produce the most milk
crossbreed selected cattle
crossbreed most productive, best offspring
over many generations

Answer 142

salt reduces water potential outside microbial/bacterial/fungal cells
microbes lose water by osmosis
cannot reproduce/survive/carry out metabolic reaction

Answer 143

not appropiate to use hardy-weinberg:
population is not sufficiently large - too small
mating isnt random

Answer 144

sex linkage

Answer 145

difference in:
fur length
eye colour
face shape
colour of fur

Answer 146

artificial selection / selective breeding

production of new alleles from random gene mutation

Answer 147

homozygous: genotype with 2 identical alleles/forms of the gene

gene locus: location of the gene on chromosome

Answer 148

innate/reflex

not learned, but genetically programmed and inherited.
it's always performed in the same way

Answer 149

inbreeding - small gene pool
homozygous recessive genotypes
allele for desired trait on same chromosome as problem allele
selection for a desirable trait may be linked to another trait/ unintentionally selects for another; breeders select for looks, not health

Answer 150

entrapment
covalent bonding / attachment to an inert surface

Answer 151

genotype:
combination of alleles possessed by organism

allele:
form of a gene

Answer 152

population not sufficiently large, too small
not randomly-mated

Answer 153

males can father many offspring, mate several females
females produce only a few offspring
20% females chosen to reduce inbreeding - genetic problems if breeding pop too small

Answer 154

calculate % proportion
- as different total numbers at each site

Answer 155

only expressed when homozygous, in absence of dominant allele
not expressed when heterozygous - expression masked by dominant allele

Answer 156

impossible/difficult to count every individual
sample provides an estimate
sample made representative of the area

Answer 157

species richness: number of species in a habitat
species evenness: relative abundance of individuals of each species. describes the number of individuals there are of each species.

high biodiversity is associated with high species richness AND high species evenness

Answer 158

plants = basis of all food chains
shrubs are food for insects that birds eat

idea that shrubs may provide nesting sites/protection for woodlands birds

Answer 159

low biodiversity
habitat dominated by a few species
ecosystem is unstable, less likely to adapt to environmental change

Answer 160

phylogeny = evolutionary relationship between organisms
phylogeny is the basis of classification
molecular evidence e.g. cytochrome C, base sequence, is used to classify
organisms of the same group have shared phylogeny, common ancestor
the two lynxes are similar enough to be placed in the same genus, but sufficiently different to have been placed in seperate species

Answer 161

modern technology e.g. DNA sequencing to distinguish between species

Answer 162

impact on food chains // keystone species // controlling prey population
economic reasons - ecotourism
ethical reasons - moral obligation / duty of humans to preserve species
aesthetic reasons - beauty of nature, beautiful creatures

same for reasons for maintaining biodiversity

Answer 163

natural habitat lost due to environmental change - natural disasters, climate change, deforestation etc.
population in natural habitat is very low
in wild, reproduction is difficult if numbers are low
maintains gene pool
protection from herbivores, predators, poachers
protection from disease, pests

Answer 164

large numbers can be stored since seeds take up little space
lower maintenance to store, less labour intensive
seeds remain viable for longer periods
easier to transport
less vulnerable to disease or environmental damage

Answer 165

use quadrat
random sampling, e.g. using random number generator
place measuring tapes at right angles to produce a grid with coordinates
use of identification key
method to measure abundance (% cover)
repeat many times
sample at different times of year

Answer 166

not all areas explored, some habitats inaccessible
sampling may miss microscopic, camouflaged, nocturnal etc. species
evolution is ongoing, new species are formed
organisms become extinct
some species difficult to distinguish e.g. may mistake several species for one, may be reclassified

Answer 167

use of random sampling
use of identification key
sampling at different times of year
standardisation of sampling technique

Answer 168

variety of species // species richness + evenness
variety of habitats and ecosystems
variety of alleles

Answer 169

species wrongly identified
grey squirrels less timid, more likely to be sighted and visit public areas
red squirrels harder to see - smaller? grey squirrels more camouflaged?
red squirrels more nocturnal

Answer 170

genetic variation within species
range of habitats/ecosystems

Answer 171

CITES

Regulate TRADE:
preventing trade of endangered species
ensuring trade doesn't endanger wild populations
allowing trade in artificially propagated plants, in less endangered organisms

RIO CONVENTION

sustainable use of organisms, ecosystems - e.g. replanting trees, fishing quotas
sharing genetic resources
promoting ex situ conservation e.g. captive breeding programmes
raising profile + education of biodiversity with general public

Answer 172

use of antibiotics, vaccinations
use of pesticides/insecticides
growth supplements / steroids

Answer 173

fertiliers broken down by decomposers
adds mineral ions to soil e.g. nitrates, ammonia, phosphates
nitrates for amino acids, magnesium for chlorophyll, phosphates for ATP
may also improve soil quality e.g. neutralises acidic soil, more moisture, less soil erosion

Answer 174

promotes growth of one or few plant species
other plants are outcompeted

may change soil pH, soil quality, so some plant's cannot grow

Answer 175

loss of genetic diversity, reduced gene pool
includes loss of useful alleles/genes --> potential genetic resouce is lost
gene useful for agriculture - disease resistance, pest resistance, drought tolerance

Answer 176

increase genetic variation / gene pool
reduced chance of future environmental change/diease affecting whole population
reduced chance of inbreeding

Answer 177

application of fertiliser replaces lost mineral ions e.g. nitrates
nitrates for amino acids
nitrates are soluble - can be leached/washed from soil! needs to be replaced

Answer 178

natural selection
insecticide = selection pressure
mutation randomly and naturally occurs
resistant survive (selective advantage) // non-resistant die
resistant aphids will pass on allele for resistance to offspring
higher proportion of more resistant individuals in population

Answer 179

individuals with sufficiently different genes, unrelated
reproductive age/fertility
high proportion of females
health

Answer 180

check health
adequate food supply
protected reserve - no hunting/poaching
gradual introduction e.g. via a semi-wild habitat
involve local population and raise public awareness

Answer 181

use transect to select sampling areas
sample many times, calculate mean
standardise the sweeping procedure - same number of sweeps, same type of movement
sample at different times of year
prevent recounting, ensure insects don't escape before identified

Answer 182

measures abundance of individuals in each species
higher species evenness = higher biodiversity
low species evenness indicates dominance of a few species
useful to calculate Simpsons index of diversity
speciess evenness is more quantitative than species richness

Answer 183

biodiversity
rare, endangered species
likely reduction in size of habitat
wider effect on whole ecosystem - e.g. effect of spread of species

Answer 184

sample in wider area, e.g. using several transects
collect at different times of year
using the same collecting/identifying technique e.g. using sweep net
method of ensuring individuals not counted again

Answer 185

same genus

similar appearance, behaviour, DNA, anatomy etc.
share common ancestor, closely related

Answer 186

legal protection - no hunting
monitoring of population e.g. tagging
protected areas - e.g. reserves
increased public awareness, e.g. educating local population on importance
promotion of ecotourism
in case population falls again, sperm bank / frozen embryos
prevent habitat destruction

Answer 187

if one susceptible to the disease, all likely to be susceptible too

think about abiotic and biotic factors:

variation in weather
soil water content, rainfall
soil mineral content e.g. nitrates
number of pests, competition from other plants

Answer 188

similarities and differences in base sequence
similarities and differences in cytochrome c
similarities and differences in amino acid sequence
similarities and differences in anatomy
similarities imples close relationship, recent common ancestor
evolution in action - e.g MRSA resistance to antibiotics // selective breeding
fossils show that organisms have changed over time. fossils can be dated.

Answer 189

B, C, D are more closely related to each other than A
B, C, D share more recent common ancestor
phylogeny of B, C, D diverged at some point
A is likely a different taxonomic group from the other 3

Answer 190

more research/evidence since
improved technology, particularly in molecular evidence
the theory fits evidence

Answer 191

different islands have different habitats and selection pressures
isolation: no gene flow, geographical barriers, allopatric speciation

Answer 192

genetically identical - hence acts as control variable, no genetic variation to affect results
however, you don't see a varied response to drug like in real populations with genetic diversity. e.g. rare allergies/adverse reaction wont be seen

Answer 193

produce stem cells and grow new tissues/organs
saving endangered animals, e.g. recreating extinct animals
producing animals with desirable characteristics

Answer 194

3 domains = eukaryotes, eubacteria, archaea
based on diffences in DNA, RNA

more accurately reflects origins of prokaroytes/eukaroytes:

domains divide prokaryotes - split into two groups; reflects differences between eubacteria and archaea
e.g. differences between cell wall composition / ribosomal RNA

domain groups eukaroytes together
domain reflects similarities between eukaryotic kingdoms
e.g. all eukaryotes have nuclei, membrane bound organelles, 80s ribosomes, histones

Answer 195

directional selection:
mutation
mutation is random! spontaneous. genetic variation is pre-existing
selection pressure e.g. competition for food
individuals with mutation for echolocation more likely to survive and reproduce
echolocation alleles passed on to next generation
allele frquency for echolocation increases over many generations

Answer 196

interbreed
assess fertility of offspring
if offspring are infertile, or no offspring are produced, then different species

Answer 197

cells have no cell wall
heterotrophic
eukaryotic
multicellular

Answer 198

genetic differences, e.g. different alleles, inherited differences
can also come about by mutations, difference in environment

Answer 199

SPECIATION

isolation of populations
e.g. a geographical barrier (river, mountain), reproductively isolated
mutation! genetic variation is pre-existing
natural selection - diffrential survival, certain alleles passed on
DIFFERENT SELECTION PRESSURES IN DIFFERENT ENVIRONMENTS
different alleles selected for, and with enough time, changes in populations means they can no longer interbreed

Answer 200

MRSA is harder to treat
antibiotics will no longer work on MRSA
potential for disease outbreak - pandemic - killing many people
developing new, more powerful antibiotics is expensive, takes time

Answer 201

fossils change over time
fossils can be dated
fossils show intermediate forms, general trend of small to complex. simplest, most different from modern species are found in older fossils. fossils show links between organisms too, e.g. can find common ancestors of two species
can compare DNA extracted from fossils

Answer 202

range of values
influenced by many genes (polygenic) + environment
quantitative
no defined catergories

Answer 203

inbreeding
reduces gene pool!!!!
increased susceptibility to disease/abnormalities e.g. bone abnormalities

Answer 204

antibiotic resistant bacteria
antibiotics kill useful bacteria
antibiotic passes into human food

Answer 205

placing organisms into different taxonomic groups based on similarities / differences
more similar organisms are placed in the same group vs. different organisms placed in different groups

Answer 206

anatomy - observable features
cell features e.g. membrane bound organelles, cell wall
cytochrome C
DNA/RNA
physiology + behaviour
phlogeny and evolutionary past. how closely related certain species are

Answer 207

3 domains vs 5 kingdoms
domains are eubacteria/archaea/eukaryotes
kingdoms are prokaryotes, protoctists, fungi, plants, animals
eukaryotes split into different kingdoms, whereas all eukaroytes are in same domain
all prokaryotes in same kingdom, whereas prokaryotes split into different domains
domain classification based on rRNA, protein synthesis etc.

Answer 208

lag phase - slow increase in population from 24% to 32% during day 1.
log phase - rapid increase day 1 to day 3, to 90%
rate of increase slows during day 3
stationary phase - population levels off at 100%

Answer 209

ethanol is produced all of the time
productin of ethanol increases as yeast populatuon increases, following the growth curve for yeast.

Answer 210

adsorption
membrane seperation
encapsulate in matrix e.g. silical gel, cellulose

Answer 211

enzyme reuused so reduces cost
product is uncontaminated since product is not mixed with enzyme
reduced downstream processing costs
immobilised enzymes work at higher temperatures
reaction can be done at higher temperatures - can be faster, higher yield

Answer 212

P lag
Q log
R stationary
S death

primary metabolite = molecule needed for cell's growth and reproduction. e.g. glucose

primary metabolite production at highest rate during the log phase phase
most secondary metabolites are produced during the stationary phase
the concentration of secondary metabolites reaches a maximum at the stationary//death phase

Answer 213

oxygen - increase by adding continuous supply of oxygen, use paddles to distribute oxygen evenly
temperature - maintain at optimum, prevent denaturing of enzymes
pH - maintain at optimum using buffer, prevent enzymes denaturing
nutrient - increase nutrients by continuous addition of nutrients, using paddles to distribute evenly
preventing entry of competing microbes - use aseptic techniques

Answer 214

cell's DNA isnt being changed
the child isnt producing the HGH
the HGH is given repeatedly, its a short-term solution. its not a cure.

Answer 215

DNA that is combined from two organisms. the DNA has inserted in it the DNA from another organism.

Answer 216

somatic cell nuclear transfer:

somati cell from animal to be cloned, egg cell from an egg donor is enucleated
somatic cell fused with enucleated egg cell
electric shock [electrofusion]
grown into blastocyst, embryo matures in petri dish, in vitro
embryo implanted into surrogate mother for birth

Answer 217

advantages of cloning:

all offspring inherit the silk gene DNA, soo all will make the silk protein
many obtained in a short time

disadvantages:

all genetically identical - more susceptible to disease, environmental change
cloned animals may have shorter life spans, be less healthy
cloning sucess rate is poor
cloning is expensive and labour-intensive

Answer 218

disease causing organism

Answer 219

WHAT IS BIOTECHNOLOGY?

large scale, industrial use of organisms to produce useful products
e.g. to produce food - lactobaccilus, yeast
e.g. to produce drugs - e.g. penicillin, insulin
e.g. to make enzymes for bioremediation - sewage treatment

ADVANTAGES OF MICROORGANISMS USE

fast growth, reproduction rate
simple growth requirements - grow on waste e.g. whey
less energy used, low temp. / pressure to maintain
microbes easily gentetically engineered [e.g. insulun production]
products are easily seperated, pure, little downstream processing [e.g. insulin released in a batch fermenter is easily purified]

Answer 220

prevents unwanted microbes from entering
no competition for nutrients
no decrease in yield
no contamination of the penicillin/product
also prevents escape of peniccilum

Answer 221

microorganisms are being used to make products for human benefit

Answer 222

microorganisms killed
enzymes denatured
no competitiors, no food spoilage from hamfrul microorganisms too

Answer 223

isolate the desired gene:

use restriction enzyme to isolate insulin gene
obtain insulin mRNA
use reverse transcriptase to make cDNA; builds double stranded DNA from single stranded RNA
restriction enzyme used to create sticky ends

vector

cut open plasmid vector using same restriction enzyme!
annealing of sticky ends [ hydogen bonds]
DNA ligase join sticky ends by forming phosphodiester bonds
--> recombinant vector to transfer desired gene

transfer of vector into host cell

use marker to identify cells with desired gene, e.g. fluorescent markers
then cloned

Answer 224

keep animals warm and indoors
reduce animal movement
feed animals high energy food
vaccination/antibiotics for animals
selective breeding or genetic engineering for more productive animals e.g higher yielding

Answer 225

producer: photosynthesise, produces biological molecules, autotrophic
consumer: eats/derives energy from feeding on other organisms
trophic level: position in a food chain

Answer 226

mineral content
soil pH, acidity
water depth

Answer 227

waterlogging reduces oxygen
low pH stops many enzymes from working
decomposers not present, since few can survive these conditions

Answer 228

peat bog ecosystem takes a long time to form, difficult to replace
maintain biodiversity. loss of biodiversity and rare species

Answer 229

animals feed on plants
digest and hydrolyse proteins into amino acids
these amino acids are then aborbed into the blood and into cells
amino acids used to synthesise proteins during translation

Answer 230

C: nitrosomonas
D: nitrobacter
nitrates are soluble, enters plant
plant need nitrates to make amino acids

Answer 231

nitrogen fixation:

legume
nitrogen fixing bacteria e.g. rhizobium in root nodules
nitrogen gas converted into ammonium compounds
ammonium converted to nitrates by nitrifying bacteria (nitrosomonas and nitrobacter)

Answer 232

tropical climate:
higher temp
more sublight
rate of photosynthesis higher
greater formation of organic moleules, biomass

rainforest/woodland vs grassland:
greater biodiversity, more niches

Answer 233

pioneers arrive earlier
pinoeer community subject to more succession, usually has less biodiversity
pioneer community has a lower biomass

Answer 234

convervation maintains ecosystem, involves sustainable management of ecosystem, resources
preservation leaves ecosystems unchanged, no physical intervention

Answer 235

decomposition is break down of waste. organic matter is converted to inorganic matter

denitrification is the conversion of nitrates to nitrogen gas

decomposition increases nitrate supply whilst denitrification reduces nitrate supply

Answer 236

nitrogen fixation is the conversion of atmospheric nitrogen into ammonium compounds - rhizobium (root nodules), azotobacter (free living in soil)
nitrification is conversion of ammonium compounds into nitrites/nitrates (nitrosomonas, nitrobacter)

Answer 237

bacteria/fungi
external digestion by secretion of enzymes
absorption of breakdown products; makes ammonium compounds
(also released CO2, water)

Answer 238

helps wolf population
actively maintain biodiversity, sustainable management
prevents over-population by elk (its prey), which also prevent over-grazing - damage to habitat

Answer 239

more efficient at finding food, better adapted

Answer 240

geographical barrier, isolated
reproductively isolated - no interbreeding between populations
different selection pressures on different islands
smaller populations and therefore smaller gene pools more subject to greater genetic drift + founder effect

Answer 241

habitat destruction
urbanisation, land used for buidlings, agriculture
deforestation
more pollution
oil spills, sewage, eutrophication
hunting, overfishing
introduced animals --> competition, predation, over-grazing

Answer 242

regulatory gene
contains homeobox sequence
gene product binds to DNA, switches genes on and off
control of body plan
transcription factors

Answer 243

homeobox genes are very important
mutation would alter body plan - e.g. no arms
mutation likely to be lethal, thus selected against

Answer 244

base sequence

protein could be shorter due to deletion/stop codon or longer due to insertion
different primary/secondary/tertiary structure. different sequence of amino acids, different 3D folding
protein unchanged due to silent mutation, non-coding DNA is altered
change can be harmful, function is lost
function could be better

Answer 245

genome is too big
only small sections can be sequenced at a time
accuracy better, fewer errors with small fragments
more practical - genome can be sequenced in different labs

Answer 246

no need to test for interbreeding
common ancestor

can apply to organisms that reproduce asexually!!
can also apply to exinct organisms

module 4 and 6 Flashcards

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