Experimental Methods Flashcards
1
Q
Accuracy
A
How close a measurement/reading is to its true value
2
Q
Systematic errors
A
Faulty instruments or flaws in experimental procedure - repeated consistently
3
Q
Random errors
A
Unexpected environmental changes - different each time experiment is carried out
4
Q
Precision
A
How similar repeats/readings are to each other ; greater number of decimal places = more precise
5
Q
Reliability
A
Experiments are repeated to ensure reliability/repeatability of results
6
Q
Validity
A
Other variables are identified and controlled to ensure validity
7
Q
Different combinations of genes/alleles
A
2 to the power of number of homologous chromosomes - meiosis
8
Q
What vessels have sphincter muscles
A
Arterioles
9
Q
Lub dub
A
Closing of av and then closing of semi lunar
10
Q
Increase co2 concentration
A
Decreases pH
11
Q
Chloroplasts vs mitochondria comparison
A
Chloroplasts bigger than mitochondria
12
Q
What are stem cells in plants
A
Pluripotent
13
Q
Amylase breaking down starch
A
Into maltose
14
Q
When adding a stain…?
A
Place stain at edge of sample and not the centre
Remove excess stain using blotting paper
45 degrees
15
Q
What does using more than one stain do?
A
Improves contrast
16
Q
Ensure stain
A
COVERS WHOLE SAMPLE
17
Q
Eukaryotic vs prokaryotic
A
Eukaryotic contains membrane bound organelles
18
Q
Capture recapture formula
A
(Number in 1st sample) * (number in 2nd sample)
DIVIDED BY NUMBER IN 2ND SAMPLE THAT IS MARKED
19
Q
Action potential type of response?
A
Positive feedback loop reinforces influx of Na+ ions
20
Q
Phosphate group in ATP
A
ATP contains 3 phosphate groups
21
Q
Why do we want dna replication to produce two new genetically identical strands
A
Minimises risk of mutations - have to be genetically identical
22
Q
Test for starch
A
Iodine SOLUTION (+ potassium iodide)
23
Q
Reducing sugars test
A
Benedict’s solution + heat
24
Q
What type of sample is Benedict’s/biuret
A
Alkaline
25
Why is taking the mean into account a bad thing sometimes?
Since it includes any outliers while mode does not
26
Mitosis purpose
Gametes from haploid cells
Clonal expansion
Making new stem cells
27
What does bile do?
Emulsify lipids physically breaking them down into smaller droplets and increasing SA
28
Inspiration
External intercostal muscles contract
29
Effectors
Cannot be bones - they will be the muscles that move the bone
30
How is carbon dioxide mainly transported around the blood
Hydrogencarbonate
31
Companion cells adaptation
Lot of mitochondria
32
Adaptation of gills of fish
Stacked against each other - movement is stopped - slows down rate off low thus increases diffusion
33
Viewing the heart
Lateral cross section - staining/microscope
34
Haemoglobinic acid
H+ + Hb forms haemoglobinic acid ; acts as a buffer
35
Casparian strip
Partially permeable membrane - filters it through ; toxins are removed
36
How do assimilates move through phloem
By mass flow
They move into the phloem through plasmodesmata (H+ ions)
37
Examples of sinks
Root
Meristem - rapidly dividing
38
Phagocytes
Macrophages and neutrophils - macrophages from APCs and neutrophils carry out phagocytosis
39
Membrane functions
Site of chemical reactions - ATP synthase etc
Compartmentalisation - concentration gradients/stable environment
Allow substances to enter and leave (partially permeable)
Cell communication/signalling glycoproteins
40
Coenzymes
Vitamins
41
Cofactors
Minerals
42
Which way does water vapour flow through a leaf?
Palisade mesophyll - spongy mesophyll - air spaces
43
When measuring cell size in a microscope
Take repeat measurements at the end and calculate a mean
44
Photorespiration
At higher temperatures - oxygen competes with carbon dioxide for active site of RUBISCO thus less GP (and thus TP) produced ; RuBP is not regenerated
45
Less co2
Less carbon fixation - less TP made ; need for ATP and reduced NADP is lower which slows down light dependent stage ; ATP and reduced NADP accumulates and leads to end product inhibition
46
Fats
Are also non-polar ; thus do not affect osmotic potential
47
When you are removing glucose from free ends what are you doing
Hydrolysing glucose monomers
48
Cellulose property
Inert
49
Synthesis of polynucleotides/triglycerides
Involves formation of ester bonds
50
Triglycerides/lipids
High ratio of hydrogen to oxygen
51
Benefit of animal fats being saturated/harder
Role in protection/insulation as well as energy storage
52
Differences in species how determined
Cytochrome C
RNA polymerase
53
How to improve uncertainty
Use more precise equipment callipers etc
54
Problem with using colorimeter on a leaf
Accessory pigments/chlorophyll are also present which may interfere
55
Pressure in lymph
Low
56
Primary defence mechanisms
Blood clotting
57
Small isolated populations
Can be easily wiped out by disease
58
Disadvantage of no organelles in erythrocytes
No respiration from mitochondria
Does not divide
Protein synthesis
59
Explain differences in size of organelles/specimens?
One’s been cut longitudinally the other transversely
Some organelles are undergoing mitosis/beginning to divide
60
Purpose of mitosis (apart from growth/repair/AR)
Maintaining set number of chromosomes
61
Advantage of umbilical cord stem cells
Easier to extract/harvest
Can be stored for the future
62
Trunk swelling outside
Hydrostatic pressure has increased somehow water comes into the cells
Or cells are rapidly dividing
63
Lignin in xylem
Waterproofing
64
Glycoproteins
Cell adhesion - big role in holding them together in tissues
65
Artery collagen
Thick - strengthens against pressure of the blood
66
Smooth muscle arteries
Contract - direct how much blood flow
Maintain pressure alongside elastin - stretche/recoil
67
Lumen
Smooth - reduces friction as blood flows through
68
Coronary heart disease factors
Saturated fats
Obesity
Age (as you get older)
Diabetes
Gender
69
Risk factors for type 2 diabetes
Age
Genetic history
Gender - more common in males
Obese
Sedentary lifestyle
70
Adaptations to respire longer anaerobicallu
Tolerant to lactate/low ph/high CO2 concentration
Greater affinity for oxygen
71
Faster diffusion of ions in action potential
Faster depolarisation
Shorter refractory period
72
Importance of refractory period
Ensures that action potentials are discrete events and stopping them merging into each other
Impulses can only travel in one direction
73
Tissue that lines proximal convoluted tubule
Columnar epithelial
74
Purpose of microvilli in PCT
Increase SA allowing greater volume of filtrate to be reabsorbed
75
PCT
Selective reabsorption - using Co-transport/active transport
Water follows by osmosis so concentration of ions/urea in filtrate increases
76
Anticoagulants haemodialysis
Stop blood clotting in the machine
Afterwards they are removed to allow blood to clot normally
77
Why are cells packed together in PCT
No fluid can pass between the cells ; must pass through cells
78
Urethra
Leaves body - excretion
Ureter is from kidney to bladder
79
What to ensure when doing photosynthesis experiments?
Ensuring CO2 is in excess
80
Erector pilli response in fight or flight
Makes the animal look bigger
81
Hypothalamus nervous system?
Also a part of nervous system - osmoreceptors are nervous system ; NEGATIVE FEEDBACK CYCLE
82
Atrial fibrillation
Has taller QRS complex - shorter squiggly lines between them
83
Why do aerobically fit people have smaller heart rate?
Increased stroke volume
Thicker heart muscle
Increased ventricular volume
84
How do calcium ions go back into sarcoplasmic reticulum
Via active transport
85
High respiratory quotient like glucose vs fats (low RQ)
More oxidised - requires less oxygen
Fatty acids are less oxidised - low respiratory requiring highest amount of oxygen for complete oxidation
86
Where do chloroplasts store food?
Starch grains
87
What type of light can penetrate furthest through water
Light of shorter wavelength
88
Reasons for why you need to work fast in an experiment
Minimise evaporation of any solvent/liquids - reduce degradation of pigments
89
Why is ice cold ethanol and sucrose used?
To slow down rate of enzyme reaction and prevent damage to chloroplasts
90
What does high temperature do to chlorophyll pigment
Destroys chlorophyll pigment
91
What is a limiting factor?
A factor that determines the rate of the reaction at lower levels
92
Microorganism population growth
Original population * 2^n
93
Where is light chain on antibody
OUTSIDE BIT
94
Primary immune response
Relatively slow production of a small number of correct antibodies the FIRST TIME A PATHOGEN IS ENCOUNTERED
95
How to increase reliability?
Calculate a mean - measure more cells ; discard anomalous ones etc
96
What accepts hydrogen in anaerobic respiration yeast?
Ethanal
97
Advantage of anaerobic respiration?
Allows glycolysis to take place
98
Release of insulin
Low glucose concentration - resting potential - K+ ions can move out of KATP channels - maintains resting potential
High glucose level - glucose moves in via transporter and metabolised to produce ATP via aerobic respiration ; inhibits opening of potassium channels - closes K+ ions moving out ; causes membrane to depolarise and Volta gated ions can move in ; bind to secretory vesicles allowing them to fuse with plasma membrane and release by exocytosis
99
Non specific methods
Blood clotting
Skin - sebum ; flora
Chemicals - mucus/lysozymes
100
Mast cells release
Histamines (heat+redness) and cytokines attract phagocytes
101
Clotting factors
Turn prothrombin into thrombin - fibrinogen into fibrin - mesh together + collagen and seal the wound
Positive feedback
102
Seed germination
Gibberellins - released ; digestive enzymes break down food stores to release glucose for growth
103
Cell elongation
Auxin binds to receptor - H+ ions pumped in - low ph levels causing cellulose become more flexible/stretchy and absorbs water
104
High auxin concentration
Apical shoot growth
Less lateral shoot growth
105
Low auxin concentration
Low apical shoot growth
More lateral shoot growth
106
Why May you want fewer gibberellins in plants?
Less waste
Prevent crop damage by bad weather
107
Chlorosis
Plant environmental variation causes change in phenotype - leaves look yellow
108
Causes of chlorosis
Lack of light - turn off chlorophyll production to conserve resources
Mineral deficiencies - lack of iron or magnesium - plant cannot make chlorophyll
Virus infection - interfere with metabolism
109
Codominance
2 different alleles for a gene both equally as dominant thus both expressed (pink flowers - red and white)
110
Blood group
IA IB - codominant
IO - recessive
111
23rd Pair
Sex chromosomes - XX females XY males
112
Males more susceptible to sex linked diseases?
MALES ON,Y REQUIRE ONE ALLELE ON THE X CHROMOSOME TO BE RECESSIVE ; FEMALES WILL HAVE A DOMINANT ALLELE ON THE OTHER X CHROMOSOME
113
Haemophilia
No clotting protein - very slow process
114
Faulty haemophilic gene X^h
115
I^o
No antigen on the surface of RBCs hence they are universal donors - no immune system rejecting that RBC since there is no antigen
116
Dihybrid
Both genes inherited as separate units
117
Dihybrid
2 genes - each gamete - 2 alleles
118
Unexpected ratios due to
Autosomal linkage (no crossing over occurred to separate these genes)
Random fertilisation
119
If chi squared significant
Then linkage/epistasis has occurred
120
Epistasis
A gene on a particular chromosome is expressed producing a protein which stimulates or inhibits gene B expression
INTERACTION OF GENES AT DIFFERENT LOCI
121
Dominant epistasis
Requires gene A to be AA or Aa to produce protein to express B
122
Recessive epistasis
Chromosome A produces aa (recessive) - does not produce protein and thus B not expressed
123
Assumptions of hardy Weinberg
Assuming random mating
No mutations
Large population size (migrating)
No selection pressures (evolving)
124
What is hardy Weinberg
In a stable, non-evolving population - allele frequencies stay constant
125
4 major factors that affect evolution
Mutation - genetic variation ; advantageous allele
Changes to population size - density dependent factors (competition - affect size)/density independent factors (regardless of size - climate change/natural disasters)
Genetic drift - prevalent in small populations ; random mutation/selection pressure
126
Gene flow
Alleles from one place to another - migration (seasonal often) SMALL CHANGE
127
Genetic bottleneck
LARGER change - irreversible change to total number of alleles ; natural disasters - affects future generations - alleles decreases
128
Founder effect
Genetic drift - mutation from small gene pool that gives favourable gene which can outcompete rest of population forming a new colony
129
Founder effect
A few individuals’ alleles eventually form whole new populations
130
Selection of favourable alleles (4th factor affecting evolution)
Sexual selection ; more alleles that promote mating success (passing on this allele)
Natural selection - more alleles that promote survival success
131
Stabilising selection
NORMAL DISTRIBUTION
AVERAGE PHENOTYPE IS SELECTED (SPIKE IN MIDDLE) ; BABY WEIGHT ; UNDERWEIGHT/OVERWEIGHT LESS LIKELY TO SURVIVE - PASSING ON GENE FOR BABIES WITH NORMAL WEIGHT TO BE BORN
132
Directional selection
One extreme is favoured - industrial evolution selection pressure of moths ; population of darker moths increases
133
Disruptive selection
Both extremes are selected
Duller feathers left alone survive longer
Bright feathers too frightening left alone survived longer
Can mate and pass on genes
134
Speciation precursor
Always underlying genetic variation
135
Allopatric
Physical barrier has separated population subject to different selection pressures - different genotypes/alleles are favoured (selected and survived and passed on - hence genotype and phenotype more prevalent)- CHANGE IN ALLELE FREQUENCY due to new habitat
136
Allopatric speciation
Just happen over several generations
137
Sympatric speciation
Happens in same habitat - mating preferences/disruptive selection causing new species to form
Much rarer
Physically cannot recognise other members of same species due to variation
Only reproduce with those that animals could recognise (selective breeding is similar to sympatric speciation)
138
Faeces
COLOURED FROM BILE
139
How to show uncertainty
If error bars overlap
140
Collagen
Glycine
141
Cysteine
Has many disulfide bridges
142
As you increase temperature of cell surface membrane
GAPS BETWEEN PHOSPHOLIPIDS INCREASE - PERMEABILITY INCREASES
143
How does frosting/defrosting impact cell surface membrane
Ice/water expansion damaged membrane (punctures it) increasing permeability
144
Why are there two tubes in a respirometer?
Compensate for temperature changes by evening out the pressure on both sides
145
Why is there a filter paper with KOH solution in respirometer
Increase SA for CO2 absorption
146
Rate of movement of water in pathways?
Movement of water in symplastic is slower than apoplastic
147
Pancreatic exocrine function
Pancreatic juice into duodenum/digestive enzymes to epithelium in a vessel
148
If asking for other possible factors always mention
Possibly epigenetics factors
Other underlying health diseases
149
Downside of stem cell
Risk of cancer
150
Liver cells adaptation
Thin/flat cells
Increase rate of diffusion
Fenestrations also increase permeability
151
At the sinks of plants
Sucrose is converted back into glucose to be used for respiration/stored as starch
152
Myosin molecules
Fibrous protein molecules with a globular head
153
What required ATP in muscle contraction
Return of calcium ions into sarcoplasmic reticulum and return movement of myosin head that causes actin filaments to slide
154
How is ATP supplied for muscle contraction
Aerobic respiration takes too long ; anaerobic respiration is still 10 seconds - phosphocreatine is a molecule stored by muscles that can be used for rapid production of ATP
155
Equation of phosphocreatine
Phosphate ion from phosphocreatine + ADP -> ATP + creative
156
When is phosphocreatine utilised
Muscles of a sprinter - continuous contracting until mitochondria is able to supply ATP ; afterwards once used up then rate of muscle contraction must EQUAL rate of ATP production (from both aerobic and anaerobic respiration)
157
Cardiac muscle
Have intercalated discs help in contraction + striated
158
Smooth
Pupil size
Bladder
Digestive systems
Bronchioles etc
159
Myofibrils
Long cylindrical units
160
Whenever an ion binds
CONFORMATIONAL CHANGE
161
Cardiac output
Stroke volume * heart rate
162
Formation of urea equation
Requires co2 and nh3 ; water is what is converted to urea when going from arginine to Ornithine
163
What happens to lactate in anaerobic respiration
Broken down by oxygen in the liver (oxygen debt) turned into glucose
164
Functions of liver
Formation of urea
Storage of glycogen
Detoxification
165
Urea vs ammonia
Urea is less soluble and less toxic
166
Hormone metabolism
Protein hormones like insulin and glucagon are hydrolysed into amino acids which are then converted into urea
167
Peptide hormones
ADH
168
Dehydrogenase
Used wherever there is a transfer of a hydrogen atom from an organic molecule to an inorganic one
169
What substances ionise in respiration
Pyruvate
Citrate
OAA
170
What occurs at the cristae
OXIDATION OF NADH
171
Where is proton gradient in chloroplast
Thylakoid membrane
172
Diameter tubing questions
Figure out surface area of bubble using RADIUS given
Then multiply by length/any rate given
173
End point of dcpip
Pink colour - not colourless
174
Increase in concentration for every 1 unit
Final value/initial value divided by (difference of NUMBER OF UNITS)
175
Why is it best not to add indicator to the test tube
As it may affect the progress of the reaction
176
How to improve validity of sample taking
Take samples at more frequent intervals
177
How to increase validity if an experiment
Add buffer to control pH
178
Little variation
High repeatability
179
What do error bars do
THEY OVERLAP
180
Gas collected
= water displaced
181
Commercial effect of inhibitor
More inhibitor wastes money
182
Planning an experiment
Variables
Repeatability (quantitative processing for example)
Risk Assessment
Scientific apparatus
183
How would water on the leaves affect transpiration rate
Water could block the stomata
184
Hydrophytes
Water lost is easily replaced - plentiful water
185
How does ph affect rf values
Ph of the solvent influences rates at which X and Y migrate
186
How high should solvent line be
1 cm away from amino acids to prevent the acids dissolving
187
How to improve resolution of TLC
Use longer filter paper
188
How does increase temperature affect heart rate?
Increases heart rate to get rid of excess heat by dilating arterioles (and thus capillaries)
189
Why are daphnia used?
Fewer ethical considerations
190
A fitter person
Has greater stroke volume
191
What do gibberellins do?
Seed germination
Prevent leaf abscission
192
One plant variable hard to control
Surface area of the leaves
193
When using sensors
Ensure they are the same distance away
194
Why are respirometer flushed/cleaned out?
To remove any microbial growth/reset it back to zero - they are washed with hot water
195
Using colorimeter
Objective = less bias
196
To reduce uncertainty
Use callipers/more precise equipment
197
Practical error with water potential
Could be inadequate drying
198
Repeats =
Reproducibility
199
How do H+ ions affect cell membrane?
They affect ionic bonds of the membrane proteins
200
What do free divers have
High co2 tolerance
201
Why do we calculate a mean
To reduce uncertainty (anomaly) - reduces random error too
202
Reproducibility
Similar results produced by different investigators with different equipment
203
Not touching the TLC plate
No contamination of oil/bacteria from fingers
204
Negative control
One thing you change to ensure that it is the variable you are changing that is causing the change - add buffer/boil yeast whatever
205
Tidal volume
Normal breaths in and out
206
Everything except - volume
Everything except residual volume is = vital capacity
207
Ribcage cavity
THORAX
208
In the leaf of a plant
The phloem is straight after the xylem - IGNORE CAMBIUM
209
When asking for serial dilutions
Make sure to see if it’s ORIGINAL 1 mol dm^3
210
Cardiac muscle
Is branched and interconnected
211
Cardiac muscle
Is branched and Interconnected
212
Where is ATP needed in muscle contraction
Break cross bridging and detaching myosin from actin - allows for muscle relaxation
213
Phosphocreatine ATP
Runs out in a few seconds
214
Glucocorticoid
Regulates carbohydrate metabolism
215
Why are computers good
Continual data collection
216
Intracellular reactions
Catalase breaking down hydrogen peroxide
217
Extracellular reactions
Trypsin or amylase
218
Membranes
Sites of chemical reactions
219
Active transport explain
Molecule comes along binds
Causes hydrolysis of ATP to ADP and pi
Inorganic phosphate ion binds to carrier protein causes change of shape against concentration gradient
Released and then ADP + inorganic phosphate creates ATP again
220
Neuromuscular junction
Between neurone and a muscle - they can only ever be excitatory while cholinergic synapses can be both excitatory or inhibitory
221
Elastic fibres
Present in all parts of the gaseous exchange system
222
Support in insects
Chitin around tracheae - impermeable to gas exchange
Like c shaped cartilage in trachea of humans
223
Water in tracheoles
Dissolve and easily DIFFUSE ACROSS MEMBRANES
224
A control set up is one
WITHOUT THE INDEPENDENT VARIABLE - SHOWS THAT IT IS IV THAT US CAUSING CHANGE
225
How do you improve reliability?
Large sample size
226
Function of Hepatocytes
Produce bile - breakdown of haemoglobin in erythrocytes
227
What happens in pelvis of kidneys
All the urine collects before travelling to bladder
228
What does ADH do?
Increases PERMEABILITY to water
229
Monoclonal antibodies
Coloured dyes
230
Creatinine
Breakdown product of muscles - directly measures kidney failure
231
Kidney failure can lead to
Electrolyte imbalance
Excess Urea
232
Refractory period responsible for
Producing discrete impulses - each one separate
Ensures that they are unidirectional
Limits the number of impulse transmission
233
Abscission caused by
Lack of auxin
Promotes ethene production
That is what causes enzymes breakdown of separation layer/abscission zone
234
Antifreeze
ABA produces antifreeze to prevent the cytoplasm in cells from freezing
235
Weed killer uses
Auxin
Also in seedless fruit x auxin
236
At a neuromuscular junction
End point of action potential
237
Photo system = light harvesting + reaction centre
238
PSII
700 nm
239
In respiration Krebs cycle
Per cycle 1 atp produced
240
Ame length of dna bases
Must be a mutation - same number of bases
241
TLC
Adsorption onto stationary phase
Soluble in mobile phase
242
When does dehydrogenation occur?
Whenever NADH or FADH2 is produced is when dehydrogenation occurs - ATP produced
