bio paper 2 Flashcards
(89 cards)
1
Q
ecosystem meaning
A
all the living organisms and physical conditions in an area
2
Q
community meaning
A
the organisms within the ecosystem
3
Q
habitat meaning
A
the area of the actual ecosystem
4
Q
population meaning
A
total number of each species
5
Q
biomass meaning
A
mass of living material present
6
Q
taxonomy levels
A
domain
kingdom
phylum
class
order
family
genus
species
dear king phillip came over for good soup
7
Q
abiotic factors
A
light intensity
temperature
moisture level
soil pH
8
Q
interdependence meaning
A
how different organisms depend on each other within a community
9
Q
mutualism meaning
A
both organisms benefit from the relationship
10
Q
parasitism meaning
A
the parasite gains whereas the host suffers
11
Q
how biomass is lost
A
respiration
egestion
excretion
12
Q
classification meaning
A
process of sorting living organisms into groups
13
Q
scientific names of organisms
A
first part is genus
second part is species
species is unique
genus is shared with close relatives
(like japanese names)
14
Q
continuous vs discontinuous variation
A
continuous - can be any value
discontinuous - falls into distinct groups
15
Q
mutation meaning
A
occurs when the sequence of DNA bases is altered
16
Q
evolution meaning
A
the gradual change in a species over time
17
Q
disease meaning
A
a condition caused by any body part not functioning properly
18
Q
pyramids of biomass
A
biomass of producers, then primary consumer (going up the food chain)
with a pyramid of numbers, it’s the number of the organisms
19
Q
efficiency of biomass transfer
A
only transfers around 10%
biomass available after transfer/biomass available before transfer x 100
20
Q
the 5 kingdoms
A
animalia
plantae
fungi
protista
prokaryota (monera)
21
Q
decomposers meaning
A
microorganisms (bacteria/fungi) which break down/decay dead organic material/waste
22
Q
decomposers vs detritivores
A
detritivores are small animals that break down dead material
earthworm - leaves
woodlouse - wood
maggot - animal material
23
Q
how do decomposers release nutrients
A
decomposers release enzymes
enzymes digest dead matter making it soluble
the soluble products are absorbed by the fungus
24
Q
factors affect rate of decomposition
A
warm temperature
moist environments
aerobic conditions
25
variation meaning
differences within a species
26
asexual reproduction pros and cons
+ parent well adapted, then offspring will be, because identical
+ only 1 parent needed, so reproduction faster, large number of offspring produced quickly
- adverse changes may destroy species as all will be affected
27
sexual reproduction pros and cons
+ variation allowing higher chance of survival
- requires 2 parents, so slower and fewer offspring made
28
process of meiosis
dna replication
line up in the middle
genetic recombination
pulled apart
cell divides
line up in the middle again
divide again
gametes woo!
29
allele meaning
different forms of a gene
30
examples of dominant vs recessive traits
dominant:
dark, wavy hair
brown eyes
freckles
straight nose
free ear lobes
projecting chin
recessive:
straight blonde hair
blue eyes
joined ear lobes
upturned nose
no freckles
receding chin
31
fossil meaning
formed when animal or plant remains are preserved in rock
32
how are fossils formed
organism dies
falls to the ground
flesh rots
skeleton covered in soil/sand/clay before damaged
skeleton becomes mineralised and turns to rock
rock shifts int he earth with fossil trapped inside
fossil emerges as rocks move and erosion takes place
33
how are pathogens spread between animals
through cuts in the skin
through sharing food/drinks
by inhaling pathogens
through sex
34
how are pathogens spread between plants
vectors like insects
direct contact of sap
wind
35
layers of a leaf
waxy cuticle
upper epidermis
palisade mesophyll
spongy mesophyll with the vascular bundle
lower epidermis with the guard cells and stomata
36
how does the cuticle defend the plant
stops pathogens touching epidermal cells
hydrophobic so prevents water gathering so prevents fungal pathogens
prevents water loss so for aquatic plants thin, for dry plants, thick
37
examples of chemical defences (plants)
insect repellents
insecticides
antibacterial compounds
antifungal compounds
cyanide (toxic to most living things)
38
how does a scab form
skin cut and bleeds
collagen exposure to air attracts platelets
platelets react to air and become sticky
when sticky, platelets turn fibrinogen to fibrin
it forms a network of fibres in the cut
red blood cells are trapped forming blood clot
clot hardens forming a scab, heals the skin under and falls off
39
non specific defences of human body
skin (physical)
acid in stomach (chemical)
cilia/mucus in airways (physical)
nasal hairs (physical)
tears & saliva (chemical)
40
what are phagocytes
cells that engulfs microorganisms then make enzymes that digest it
phagocytosis
41
what are lymphocytes
make antitoxins and antibodies
antitoxins neutralise toxins made by bacteria
antibodies are proteins that bind to antigens
once bound pathogens can be ingested and destroyed by phagocytes
42
gregor mendel
experiments on peas
observes that characteristics are passed from parent to offspring
characteristics were determined by hereditary units
hereditary units are passed on from both parents (1 from each)
hereditary units are dominant or recessive
43
other evidence for evolution
rapid changes in species seen in bacteria replicating quickly
extinction (species that don't adapt die out)
molecular comparison (scientists comparing DNA and proteins of different species)
44
sampling meaning
taking observations or measurements from a small area which is representative of a larger area
45
how to sample animals
pooters (sucking on the mouthpiece)
sweepnets
kick sampling (kicking river bank)
tree beating
pitfall traps
46
how to estimate animal population size
first sample size x second sample size/number of recaptured marked individuals
47
transect meaning
samples being taken along a line
48
how is biodiversity lost
deforestation
pesticides/herbicides
removing hedgerows
overfishing
pollution
49
what is conservation
protecting a natural environment to ensure that habitats are not lost
50
conservation methods
nature reserves
captive breeding
seed banks
legal protection
education
artificial ecosystems to replace destroyed ones
51
how do nature reserves practice conservation
controlled grazing
restricting human access
feeding animals
reintroduction of species
52
captive breeding pros and cons
+ creates stable healthy population
- difficult to maintain genetic diversity
- organisms born in captivity may not be suitable for wild
53
international conservation agreements
IUCN (red list) details current conservation status of threatened animals
CITES regulates trade of wild plants and animals and their products, protects over 35000 species
54
local conservation agreements
stewardship scheme in England, farmers offered money to conserve landscape
55
indicator species meaning
organisms used to measure environmental quality
56
sulfur dioxide info
released from combustion of some fossil fuels
causes acid rain
57
lichens info
indicator species use to measure air pollution
they have no roots so nutrition is from the air
air pollutants dissolve in rainwater and that can damage lichens
58
organisms monitoring water pollution
clean - mayfly larva (nymphs)
low pollution - freshwater shrimp
high pollution - water louse
very high pollution - sludgeworm
59
food security meaning
ability of human populations to access affordable food of sufficient quality and quantity
60
factors affecting food security
changing diets (meat is more energy intensive)
climate change
new pests and pathogens may evolve
61
intensive farming meaning
intensive farming aims to produce maximum product yield from minimum area of land
fertilisers and pesticides
maximising animal growth rates
minimising labour input (using machinery)
62
sustainable food production meaning
fish farming
spread manure instead of artificial fertilisers
crop rotation
biological control (allowing predation)
hydroponics
63
incubation period meaning
time delay between pathogens entering body and feeling symptoms
64
how do viruses 'reproduce'
viruses attacks cell
inserts its genes
tells nucleus to copy its genes
new viruses made
cell bursts releases new viruses made and destroying cell
65
incidence of a disease meaning
rate at which new cases occur in a population over a period of time
66
how to prevent spread of disease in humans
cover mouth/nose when coughing/sneezing
don't touch infected people/objects
use protection
don't share needles
wash hands
cook food properly
drink clean water
protect from animal bites
67
how to prevent spread of disease in plants/animals
burn diseased plants
can be treated with drugs
some herds may have to be slaughtered
chemical dips
fungicides
animal vaccinations
68
how are monoclonal antibodies made
mouse injected with antigen to produce antibodies
lymphocytes producing antibodies are collected
lymphocyte combined with a tumour cell to create a hybridoma cell
single cells chosen to be grown into cultures
monoclonal antibodies collected and purified
69
how are monoclonal antibodies used
pregnancy tests
detecting diseases
treating cancers
70
what are antiseptics
kill or neutralise all pathogens but don't damage human tissue
71
what is a pathogen
a microorganism or parasite that causes disease
72
aseptic technique meaning
an approach to working preventing cross-contamination from unwanted microorganisms
ensures apparatus/environment remains sterile
73
aseptic techniques examples and reasons
wipe down with alcohol before and after working - ensure no microorganisms in area
wear gloves - prevents them passing from sample to skin
autoclave glassware/apparatus before/after working - prevents unwanted contamination
work close to bunsen burner - prevent unwanted organisms falling into open sample
74
harmful substances in smoking
tar - carcinogenic
nicotine - addictive, makes heart faster, narrows blood vessels
carbon monoxide - attaches to haemoglobin instead of oxygen so less oxygen, causes heart disease
particulates - causes emphysema
other substances - paralyse ciliated cells lining airways, mucus gets into lungs, causes bronchitis
75
why is ethanol in alcohol dangerous
ethanol is a depressant
slows nervous system
blurred vision, loss of balance, heightened emotions
toxic to humans
liver filters it out
causes cirrhosis
76
CVD meaning
a disease of the heart or blood vessels
77
factors affecting CVD
diet, exercise, smoke, stress, genetics
78
medicines for CVD
statins - reduce blood cholesterol, prevents formation, liver removes more (upset stomach)
antiplatelets - reduce stickiness of platelets, less clotting (internal bleeding)
beta blockers - reduce high bp, blocks effect of adrenaline, slows heartbeat, improves blood flow (dizzines and tiredness)
nitrates - widen blood vessels by relaxing blood vessel walls (headaches and dizziness)
79
how is CVD treated surgically
replacing valves
widening partially blocked arteries using a stent (angioplasty)
bypassing blocked arteries using blood vessels from other areas of body
heart transplants
80
what is gene therapy
placement of functioning allele into cell containing faulty one for the same gene
81
gene therapy steps
cut out normal version of gene from healthy person
produce many copies of it
insert it into sick person using virus
82
what could go wrong in gene therapy
healthy alleles may not go into every target cell
healthy alleles may join chromosomes in random places and not work
treated cells may be naturally replaced by patient's untreated ones
83
the main STIs
chlamydia (bacteria)
gonorrhoea (bacteria)
genital herpes (virus)
HIV (virus)
HIV causes AIDS
84
how to genetically modify organisms
identify desired gene
restriction enzymes to cut gene from donor DNA
staggered cut leaves unpaired bases called sticky ends
use SAME restriction enzymes to cut open bacterial plasmid
ligase enzymes rejoins donor gene and marker gene to form a recombinant plasmid
plasmid inserted into bacteria to make transgenic organism
cultured, mutliply
purify bacteria, extract desired product
85
plant diseases
bacterial plant diseases cause tumour like growths - crown gall disease
viral plant diseases cause discolouration - tobacco mosaic virus
fungal plant diseases cause white substances - powdery mildew
86
how are plant diseases identified in the field/in the lab
in the field:
observation (you can see the symptoms)
microscopy to identify pathogen
in lab:
DNA analysis
identification of antigens on surfaces (chemical analysis)
87
preclinical testing
testing done before done on living organisms
(so on tissue cultures)
88
clinical trials and the 3 stages
tested on animals to see side effects
tested on healthy volunteers to see if safe
tested on patients to see effectiveness, safety, dosage and side effects
89
history of genetics
gregor mendel
miescher discovers nuclein (DNA)
avery proved genes are made up of DNA
chargaff found out DNA contains equal amounts of cytosine and guanine, and thymine and adenine
wilkins and rosalind franklin image DNA using x-rays
watson and crick identify the double helix structure of DNA
scientists discover individual genes coding for inherited diseases
wilmut creates clne dolly the sheep
human genome project complete
