PAST PAPERS Flashcards
define herd immunity threshold?
The herd immunity threshold is the density of resistant hosts in the population required to
prevent an epidemic
How do SDS-PAGE separates proteins by
Size
Why is serum used in cell cultures for neurons
To provide growth factors
State one way to stop harming animals can be used
Refinement, reduced,
Name a benefit of en vivo type of trials
Allows effect of drug/thing on organism to be observed
State the effect a NaKATPase pump do
Generate ion gradient for resorting membrane potential for neurons
Name the process by which response within the cell is triggered by binding ADH to its cell surface receptor
Signal transduction
Name the type of cell which undergoes meiosis
Gamete mother cell
Name the process that ensures haploid gametes produced by meiosis contain a mixture of chromosomes of maternal and paternal origin
Independent assortment
What is a representative sample
Sample which has the same mean and the same degree of variation about the mean
Which pair of cells are fused together to produce monoclonal antibodies
B lymphocyte and myeloma
What is a species specific stimuli
Species sign stimulus within the same species of showing courtship behaviour by males to females
En vivo observations are made in what
A living organism
Why are rod cells more sensitive than cone cells at low light intensities
Higher degree of amplification
Name an additional wavelength range that most birds have
UV
Describe the mechanism of signalling molecules cause effect within target cell
Diffused through membrane and binds to specific receptors to turn of transcription
Why may a steroid hormone have different effects in different tissues
Different genes are switched on or off
How is protein electrophoresis is sided to separate proteins
Apply charge/current and it’s used to separate proteins on basis of charge/shape/mass
Explain how an antibody would detect the presence of its (body) enzyme
Antibody labelled
Colour change detected if antibody was bound to Body/enzyme
Describe how genetic control determines the phenotype of maleness in mammals
The presence of a Y chromosome
Describe how an environmental factor can influence sex ratio of offspring
Temperature of incubation
When females inherit a deleterious allele on one of their X chromosomes they are less likely to be affected by its effect. Explain this?
X chromosome inactivation is random
Only half of the cells in any tissue will have a working copy of the gene
If females have more than a male gene products, what can it lead to?
Double dosage of gene products
Name some environmental factors for sex and sex ratio
Temperature, size, competition, parasitic infection
What are primary cell lines
A limited number of cell divisions and are sourced directly from normal animal tissue
A decrease in activity of glucose symport proteins in the cells lining the small intestine could be caused by an increase in what?
Sodium ion concentrations
What does the term monoclonal mean
Produced by a cell line
What substance is added to when B lymphocytes and hybridomas are fused
PEG
Describe role of bacteriorhopsin in archea
Absorbs light to pump protons
To generate ion gradient
What makes different animals see different wavelengths of light
Different forms of opsin
What is latency
Time between stimulus and response
What is frequency
How often a behaviour occurs
What is duration
How long a behaviour lasts
What should you avoid when testing an animals behaviour
Anthropomorphism
Suggest why a new vaccine needs to be developed annually
Loss of memory cells each yr
Change of surface proteins
New antigens contain new antibodies
What is meant by a hermaphrodite
When a organism has both male and female organs
A male dies and a female will undergo a period of growth and will change sex. State another cause of sex change in organisms
Competition or parasitic infection
Suggest an advantage of greater sized males/sex changed females
Male male rivalry/greater protection for females/ getting larger territories
Make notes under transduction and hydrophilic signalling molecules
Neurotransmitters
Peptide hormones
Receptors are transmembrane proteins
Binding at plasma membrane
Binding receptor makes a conformational change
Bringing about a response to cell
Write notes under diabetes and insulin
Bing of insulin to its receptor triggers glut4 recruitment
Fat and muscle cells
Type 2 with obesity
Exercise increases glut 4 recruitment
How are cyclin-dependent kinases produced
As the cell size increases during G1, cyclin proteins accumulate and combine with regulatory proteins
What do Active CDKs cause
Phosphorylation of target proteins which stimulates the cell cycle
In the G1 phase if a threshold phosphorylation is met what can occur?
The cell cycle can move to next stage (S)
In the G1 stage, if insufficient threshold of phosphorylation is reached what can occur
Cell is stopped at checkpoint
Go into G0 rest state
What is the retinoblastoma protein
It’s a transcription factor inhibitor
The transcription factors of the Rb proton is required for what and in which phase
DNA replication and in S phase
When binding the Rb to the transcription factor what is inhibited
The transcription genes to enter S phase
What is the p53 protein
Transcription factor that stimulates DNA repair, arrest the cell, or trigger cell death
If DNA damage occurs what can the p53 gene do?
Stimulates DNA repair and cell arrest
If the damaged DNA can not be repaired what can the p53 protein do?
Stimulate cell death by apoptosis
Describe how Caspase works
Break down proteins
What enzyme is used for breaking up ATP
ATPase
Which phase in cell is the Retinoblastoma phosphorylated to all the cell to go onto the next stage
G1
In Symport, is sodium high or low outside of the cell
High
In symport, is glucose high or low outside of the cell
Low
Which of the following is a non-specific immune response to a parasite?
A apoptosis induced by tea lymphocytes
B presentation of antigens by phagocytes
C apoptosis induced by natural killer cells
D production of antibody by B lymphocyte clone
C
What’s the location of insulin binding site and mechanism of signal
Extracellular
Phosphorylation
