VCAA approved definitions, processes & functions Flashcards
(95 cards)
1
Q
Gene regulation:
A
Either of:
• genes are only activated/transcribed when required
• required genes are expressed, which can save energy.
2
Q
Condensation reactions
A
Mention name of the reaction
Water is an output
Energy/ATP is an input
3
Q
• Active site:
A
a particular position/specific site on an enzyme which attaches to a specific substrate.
4
Q
Primary structure of protein
A
sequence of amino acids
5
Q
secondary structure
A
the coiled or pleated structure within the chain (including α-helices and β-pleated sheets)
6
Q
Tertiary structure
A
the overall 3D structure composed of secondary structures
7
Q
Quaternary structure
A
two or more polypeptide chains joined together
8
Q
Pathogen
A
causative agent of disease
9
Q
• Autoimmune disease
A
a disease in which the body identifies some self cells as non-self and attacks them.
10
Q
Stratigraphy
A
where layers of sediment build up over time, and the oldest fossils are found in the lowest stratum
10
Q
Active immunity
A
when a person produces their own antibodies and memory cells.
11
Q
Gene pool
A
the complete set of alleles present in a population
12
Q
Genetic drift
A
the change in allele frequency in a population due to chance
13
Q
Bottleneck effect
A
a severe reduction in genetic diversity due to a catastrophe that may change allele frequency
14
Q
Selection pressure
A
a factor in an organism’s environment that removes the unsuited individuals
15
Q
Selective breeding vs random mating
A
In selective breeding humans choose organisms with a desirable trait and breed them.
In random mating each organism has an equal chance of mating with each other
16
Q
Extinction
A
when no members of a particular species exist
17
Q
Convergent evolution
A
when two species, which do not share a recent common ancestor, independently develop similar features due to similar selection pressures
18
Q
Gene therapy
A
aims to insert a normal, functioning allele into the cell (through a virus or liposome vector)
19
Q
Hybridisation
A
the joining of complementary DNA from different sources
20
Q
tRNA function
A
carrying specific amino acids to a ribosome & complementary anticodon to codon in mRNA strand being translated
21
Q
mRNA function
A
to carry information from the nucleus to the ribosome for protein synthesis
22
Q
rRNA function
A
structural component of the ribosomes
23
Q
RNA polymerase function
A
involved in transcription; copies DNA template and by joining nucleotides
24
Nucleus function in translation
contains the code for protein synthesis
25
• mitochondria function in translation
provides energy required for protein synthesis
26
ribosome function in translation
site of protein synthesis
27
mRNA function in translation
carries code for protein synthesis
28
Function of memory B cells
rapidly produce antibodies during future infections
29
Exons function
are joined to form mRNA and are translated
30
Introns
sections of pre-mRNA removed when splicing occurs
31
Redundancy
: one amino acid is coded for by more than one triplet/codon
32
Transformation:
the process in which a bacterial cell takes up a plasmid and expresses the genes of the plasmid
33
Cloning:
making genetically identical copies of organisms
34
Probe:
a single-stranded segment of DNA which is radioactively labelled
35
Function of phagocytes
* recognise, engulf and destroy foreign material such as pathogens • engulf antibody-antigen complex
* display the antigens of ingested pathogens to trigger an immune response. Any one of the above responses was acceptable.
36
Function of complement proteins
* attach to invading micro-organisms
* make it easier for phagocytes to ingest
* lyse plasma membranes of pathogens, not cell walls
* promote inflammation.
37
Function of antibodies
bind to specific pathogens/antigens and cause agglutination so macrophages can then engulf and destroy them
38
Interferon functions
interferons are produced by viral infected cells and warn nearby cells and make them more resistant to infection by stimulating production of antiviral proteins
39
Plasma cell function
to produce specific antibodies
40
Allopatric speciation steps
* Two populations are divided by geographic barrier with no gene flow/migration between them
* Each group experiences different selection pressures and different mutations accumulate, which allow differences in allele frequencies to develop
* Over time, the populations, if reintroduced, would be unable to produce viable fertile offspring together
41
Speciation steps
* Within an original species, genetic differences accumulate
* Through natural selection individuals with suitable characteristics survive and reproduce
* Due to a survival advantage, this group develop and over time evolve into a new species
42
DNA hybridisation steps
* isolate single DNA strands from lemur species by heating, for example to 94 °C . mix the single stranded DNA from both species together and allow these strands to cool
* similar strands of DNA with complementary bases from different species reform. This hybrid DNA is reheated and the melting temperature is determined.
* The more closely related two species are, the higher the melting temperature is.
43
How amino acids in a protein can indicate evolutionary relationships:
* Over a long time, mutations accumulate that may change the sequence of amino acids
* The more differences in the amino acid sequences the less related the two species are.
44
Fossilisation steps
* Dead organism rapidly covered by sediment
* Hidden from scavengers, undisturbed, long time, decreased rate of decomposition
* Over time the sediments form rock
45
Transcription steps
* RNA polymerase copies DNA template strand by joining complementary nucleotides
* pre-mRNA produced
* optional, depending on question: undergoes post-transcriptional modifications – introns are removed, a poly-A tail and methyl cap are added to pre-mRNA to form mRNA
46
Translation steps
* mRNA travels to ribosomes
* tRNA brings a specific amino acid to the ribosome
* tRNA anticodon joins to complementary mRNA codon
* an amino acid is added to the polypeptide chain
47
Stages in aerobic respiration
* Glycolysis: glucose is converted to pyruvate, 2 ATP produced
* Krebs cycle: pyruvate converted to carbon dioxide, 2 ATP produced
* ETC: hydrogen combines with oxygen to produce water, 32-34 ATP produced
48
Electron transport chain steps
* Occurs in cristae of mitochondria
* Electrons are passed along a series of electron acceptors (cytochromes)
* Oxygen captures electrons, which are combined with hydrogen
* Carrier molecules give up hydrogen as it is passed along
49
What happens in light dependant stage
* Water is split to form oxygen gas
* Water is split to form H+ and NADPH is formed
* ATP is formed
50
Steps in PCR
1. Heat DNA to approx. 90 degrees
2. Cool to anneal primers
3. Heat to approx. 70 degrees to extend the primer with the tac polymerase.
4. repeat
51
Immune response after recieving first vaccine steps
* antigens detected by T-helper cells
* T-helper cells produce cytokines to stimulate B cells
* B cells differentiate to produce plasma cells, which produce specific antibodies
* B cells also differentiate into memory cells
52
Allergic reaction steps
* at the first encounter, plasma cells produce IgE antibodies specific to the allergen
* antibodies bind to mast cells and act as receptors to the allergen
* when the allergen is again encountered, the mast cells release histamines which cause allergic symptoms such as swelling, itchiness, excessive mucus production and airway constriction
53
What must be done in PCR to separate the strands of DNA
Heating:
• to 90°C or greater
• to dissociate the strands
• to break the hydrogen bonds.
54
What are standards and their use?
the standard consists of fragments of known length
| • they are used to estimate the size of the samples.
55
Why the action of trp as a repressor could be of selective advantage?
when tryptophan is available, its presence prevents further tryptophan being produced
• therefore the cell does not waste energy or resources producing tryptophan.
56
How molecular regulation of xyz is regulated within a cell
xyz binding to enzyme A acts as an inhibitor
the shape of the active site is changed
substrate no longer binds
as the final product increases, the first step in the pathway decreases, thus regulating the reaction
57
Explain how antibody-antigen complexes provide protection against this pathogen
Agglutination of pathogen
allow phagocytes to engulf
immobilises pathogen
58
Passive immunity key steps
- No memory cells produced
| - Does not produce own antibodies
59
Effects of bipedalism on hominin behaviour
- Free hands so made tools, carried young
- reached higher food
- raised head to look for predators
- cultural behaviour such as ceremonies
60
Why species X went extinct even though it arose recently, while species Y has been present for even longer time
- Species X had limited genetic variation and due to (some reason) were unable to evolve
- Species Y lived in an env with more stable selection pressures
61
How would artificial insemination intervene in the evolutionary process?
Artificial insemination will influence the frequency of alleles in the next generation by one organism contributing more
frequently to the population.
62
Why do scientists believe species X is extinct
no organisms have been captured or found alive
there is no specific, named evidence such as recent remains or tracks.
63
NADPH transfers...
H+
Electrons
Protons
64
ATP transfers...
Energy
65
Describe how an adaptive immune response in initiated during a bacterial infection
Antigen-presenting cells display the antigen on their cell surface to helper T lymphocytes/helper Tcells.
66
Is it possible to develop a vaccine against thunderstorm asthma?
No
Many allergens contribute to the allergic response to the pollen fragments rather than a single pathogen.
A vaccine would lead to greater production of antibodies, which would in turn increase the response.
67
Factors that effect DNA migration in electrophoresis
the size of the molecules, as the larger molecule will move more slowly
• the charge of the molecule, as the negative charge means that DNA moves towards the
positive electrode
* the length of time the voltage is applied, as there may not be enough time for the DNA to migrate through the gel
* the concentration of the agarose, as denser agarose results in the molecules moving more slowly
68
Ethical issues relating to DNA profiling results
Possible termination decisions of foetus.
• Should a severely affected child who may
suffer be born?
• Should alternative reproductive technologies be accessed?
69
Social issues relating to DNA profiling results
Cost to society of alternative reproductive
approaches (e.g. IVF).
• Psychological implications for the parents,
knowing they are carrying the mutation.
• Societal support required: could the
government’s money be better spent
elsewhere?
70
Why making a correct identification of a pathogen is important in the control of the disease
Specific pathogens have specific methods of transfer. They may require specific methods of control such as a particular antiviral drug. Incorrect identification can lead to continued infections and spread.
or
Identify pathogen and isolate antigens. This would enable the production of a vaccine or produce a drug with a complementary shape. If the majority of the population was vaccinated or treated with this rational drug, this would greatly reduce the transmission of the disease.
71
Is it possible to state than Denisovans are a separate group from Neanderthals without using DNA analysis
It would not be possible to classify the Denisovans as a separate group from Neanderthals as the fossil sample is too small.
As both groups are extinct, one is unable to determine if fertile offspring could be produced.
72
Explain why scientists choose to sequence nuclear DNA over mtDNA
Mitochondrial DNA is only inherited from the mother (and would therefore provide very similar DNA samples to other female ancestors); however, nuclear DNA contains the whole genome.
72
Role of polymerase in PCR
Extend primers by adding complementary nucleotides
to single stranded DNA after seprating the strand by heating
73
Why do some mutations have no effect on the individual?
-occur at non coding regions of DNA
or
-the DNA triplet from the mutation produces the same amino acid redundant)
or
- mutation occurs at a non essential polypeptide
74
Why was the temperature reduced to 55C in PCR and then increased to 72 C?
the temperature was lowered to 55 °C so that the DNA primers can attach to the singlestranded DNA molecules
the temperature was raised to 72 °C as at this temperature the activity of the Taq polymerase enzyme is at its highest or optimum
complementary nucleotides would bind to the single-stranded DNA.
75
What conclusion can be made if high lvels of antibodies were found and what action would be taken?
the individual has the disease
should be isolated from other family members or they should be vaccinated.
76
Name a fibrous protein and it's function
Any one of:
* collagen, to provide strength to skin
* fibrin, required for blood clotting
* myosin, to facilitate muscle contraction.
77
Describe a distinctive property of a fibrous protein and explain how this property is due to the arrangement of it's polypeptides
Property
* strength
* flexibility
Explanation
* due to the arrangement of the polypeptides which enabled them to be stretched and return to the original shape
* parallel arrangement of protein fibres for support
78
Tissue rejection process
Both of:
* in the cell mediated immune response, T-cell mediated rejection response occurs and T-helper cells activate cytotoxic T-cells and/or NK (natural killer) cells
* cytotoxic chemicals are produced which destroy foreign cells or macrophages engulf and destroy foreign material.
79
Which immune cells are respomnsible for recognising non self cells introduced by transplant
Any one of:
* T-helper cells
* macrophages/phagocytes
* antigen presenting cells.
80
Give a type of protein and give an example of a reason why it might change in concentration within a cell
**Enzyme**: If there is a change in substrate concentration, then more or less enzyme may be produced to conserve ATP
OR
**Structural protein**: repair or synthesis of organelles if organelles are damaged due to increased or decreased temperature
OR
**Regulatory/repressor protein:** more or less repressor protein is required to inhibit or promote a reaction when there is a change in substrate availability
OR
**Transcription factors:** more or less is required for transcription if environmental conditions result in increased or decreased need for protein synthesis.
81
Advantage of using mtDNA in molecular clock
there are many more copies of mtDNA in each cell
* mtDNA has a predictable rate of mutation
* mtDNA mutations accumulate or are not repaired
* all changes in nucleotides are a result of mutations rather than recombination
* mtDNA inherited from mother only allowing for a more direct line of relationships to be established.
82
Features common to primates that disitnguish them from other mammals
prehensile or grasping hands NOT five digits
* opposable thumb(s) or large toe(s)
* forward-facing eyes NOT stereoscopic vision
* relatively large brain volume to body NOT large brain volume
* nails instead of claws.
83
Social implications of GM plants
Farmers who grow non-GM canola may sell more canola and the farmer may have an improved quality
of life OR may sell less canola and have a decreased quality of life.
* Improved nutrition for consumers and therefore less demand on the health system.
* More people have access to better nutrition as GM canola is cheaper OR more accessible than fish.
* There could be a decreased consumption of fish, which results in fish farmers making less money and
having a lower quality of life.
* Consumers may not want to consume GM food. This could lead to consumers not buying enough GM
canola and farmers having a lower quality of life.
84
Biological implications of GM food
Possible crossbreeding with non-GM canola crops leading to a change in genome of the crops.
* Potential lack of genetic variation within the GM canola crop. All GM canola plants could then die if there is a change in a selection pressure.
* Consumers may not want to eat or purchase any GM products as these consumers are concerned it is
not safe to eat.
* Less fish consumed reduces overfishing, leading to an increase in the fish population.
* Improved nutrition for consumers improves health outcomes for consumers.
85
PAM Sequence function
the location of the specific section on the target
DNA that holds the DNA onto the CRISPR complex
86
Cleavage point
Cas 9 cuts at the cleavage point (just upstream from the
PAM sequence)
87
sgRNA
binds to target DNA at a specific location just above
the PAM sequence region
88
Conditions that can be **applied** to electrophoretic gel to make DNA move
* Add the DNA at the negative end of the gel.
* * Apply a voltage/current across the gel.
* * Place the gel in a buffer solution.
89
Role of T memory cells
T memory cells survive for many years and proliferate rapidly into Th and Tc cells when the
body is exposed to a pathogen for the second time, mounting a quicker and stronger response.
90
sterile
free of pathogens
91
Describe at a molecular level how antibodies perform their function
Shape of binding site is complementary to the antigen. bind to antigen. macrophages / other immune cells can engulf/destroy it.
92
Vector
means of transfering foreign gene into a cell/organism
93
