Paper 2: Advanced Info Flashcards
PET scans
* Patient injected with radiotracer.
* More glucose is required in places with higher activity.
* Only done once or twice a year.
* Expensive.
How does age impact your likelihood to develop CVD?
Increases with age as plaque build up happens very slowly over time.
What is the definition for dominant
An alleles who’s characteristic appears in the phenotype even when there’s only one copy.
MRI scans
Magnetic field and radio wavesExamines tissues in small sections with thin slices which form 3D images.Produce finely detailed images of brain structures with better resolution than CT scans.
What does the circular DNA of a prokaryotic cell do and what is it made up of?
They are one long coiled up strand and are not attached to any histone proteins.
What is the DNA coding strand also known as?
The sense strand
Draw a Relay neurone
* Dendrites
* Axon
* Terminal branches
* Cell body not external in between Schwann cells
* Large number of connections to other nerve cells
How are sperm cells specialised for their function?
Lots of mitochondria provide energy for tail movement.Acrosome contains digestive enzymes to break down the egg cells zona pellucida and enable sperm to penetrate the egg.Flagellum allows sperm to swim towards egg cell.
How does MDMA (ecstasy) work?
MDMA increases the level of serotonin in the brain.Usually serotonin is taken back into a presynaptic neurone after triggering an action potential to be used again.MDMA increases the level of serotonin by inhibiting the reuptake of serotonin into presynaptic neurones. It binds and blocks the reuptake proteins on the presynaptic membrane.MDMA also triggers the release of serotonin from presynaptic neurones.This means that serotonin levels stay high in the synapse and cause depolarisation of the post synaptic neurones in parts of the brain that control mood.So the effect is mood elevation.
What is meant by totipotency?
The ability to produce all the specialised cells in an organism and extraembryonic cells eg placenta and umbilical cord.
How does gravity impact plants growth?
Ensuring that developing shoots reach the light while roots grow in the soil.
What the the social and ethical issues of PGD
Find out about other characterisitcs leading to concerns in the future that it could create designer baies. False results could provide incorrect information.
How do SSRI’s work?
Selective serotonin reuptake inhibitors increase serotonin levels by preventing its reuptake at synapses.
What does the rough ER do?
Folds and processes proteins that have been made at the ribosomes.
What is the basic structure of an amino acid? and draw one
What is deep vein thrombosis?
Blood clot in a vein usually leg vein did to prolonged inactivity.
How did Meselson and Stahl’s classic experiment support the theory of semi-conservative DNA replication?
Two samples of bacteria were grown- one in a nutrient broth containing light nitrogen and one with heavy nitrogen. As bacteria reproduced they took up nitrogen to make the nucleotides so gradually nitrogen became a part of the DNA.They placed bacteria from the heavy broth in the light nitrogen broth and allowed one round of DNA replication.They then centrifuged it and found that the newly replicated DNA sat in the middle, suggesting its semi-conservative.
How does ventilation detect and react to increased levels of CO2?
1- CO2 dissolves in the blood plasma making carbonic acid. 2- Carbonic acid dissociates into hydrogen ions and hydrogencarbonate ions thereby lowering the pH of the blood. 3- Chemoreceptors sensitive to hydrogen ions are located in the ventilation centre of the medulla oblongata. They detect the rise in hydrogen ion concentration. 4- Impulses are sent to other parts of the ventilation centre. 5- Impulses are sent from the ventilation centre to stimulate the muscles involved in breathing.
Explain the blot clotting process
Thromboplastin is released from the damaged blood vesselThromboplastin triggers the conversion of prothrombin (a soluble protein) into thrombin (an enzyme).Thrombin catalyses fibrinogen (a soluble protein) into fibrin (insoluble fibres)Fibrin fibres form a mesh in which platelets and red blood cells get trapped
What does the plasmid of a prokaryotic cell do and what is it made up of?
Plasmids are small loops of DNA and contain genes for things like anti-biotic resistance. They are not always present and some bacteria contain several.
What is the definition for incomplete dominance?
When a trait for a dominant allele isn’t completely shown over the trait produced by the recessive allele, so both alleles influence the phenotype.
Homeostasis
The maintenance of a stable internal environment.
Where is the sinoatrial node (SAN) located?
wall of right atrium
What social and ethical issues are as a result of prenatal testing?
Increases the risk of miscarriageFalse results could provide incorrect informationUnethical to abort?
Frontal lobe
Higher brain functioning: decision making, reasoning, planning and consciousness of emotions.
Sends information to the body via the motor neurones to carry out movements.
How does L-dopa help patients with Parkinson’s?
L-Dopa is a drug that is used to treat the symptoms of Parkinson’s disease.Its structure is very similar to dopamineWhen L-dopa is given its absorbed into the brain and converted into dopamine by the enzyme dopa-decarboxylase. This increases the level of dopamine in the brain.Higher level of dopamine means that more nerve impulses are transmitted across the synapse in the parts of the brain that control movement.This gives sufferers of Parkinson’s more control over their movements.
How does diet impact your likelihood to develop CVD?
A diet high in saturated fat increases the risk of CVD. This is because it increases blood cholesterol levels, which increases atheroma formation. Atheroma’s can lead to the formation of blood clots.
A diet high in salt increases the risk of CVD as it increases the risk of high blood pressure.
How do the rough ER and Golgi apparatus help in the formation of extracellular enzymes?
The extracellular enzymes are modified in the vesicles and then are transported around the cell and then moved to the cell and secreted.
What are 5 features of hormonal control in animals?
Chemical transmission through the bloodSlower actingCan control long-term changes eg growthBlood carries the hormone to all cells but only target cells are able to respondResponse may be widespread, such as growth and development.
What happens during the critical period so that mammals can develop their visual capacities to the full?
At birth there is overlap between the territories of the different axons. Axons compete for target cells in the visual cortex. Every time a neurone fires onto a target cell, the synapse of another neurone sharing the target cell is weakened and they release less neurotransmitters. If this happens repeatedly they will be cut back.
What are statins? Give a benefit and a risk
Reduce blood cholesterol. Which reduces atheroma formation.
+Reduce risk of CVD
-Muscle and joint pain, digestive problems and increased risk of diabetes.
How do steroid cells affect cells?
The hormone is formed from lipids and have complex ring structures.They pass through the cell membrane and bind directly to the receptor molecule within the cytoplasm.Once activated the hormone-receptor complex which acts as a transcription factor.A transcription factor turns enzyme synthesis on or off.
What is prenatal testing?
Screening unborn babies for genetic disorders.
Draw and describe Temporal summation
Several impulses arrive at a synapse having travelled along a single neurone one after the other. Their combined release of neurotransmitter generates an action potential in the postsynaptic membrane.
Stimulation the sympathetic nerve causes heat rate to?
increase
How does gender impact your likelihood to develop CVD?
More common in men due to hormones such as oestrogen as it increases the levels of HDLs in the blood.
How are genes switched on by transcription factors?
RNA polymerase is present and if all required transcription factors are present eg hormones. RNA polymerase and the transcription factors are present and bind to the promoter region which is adjacent to the gene to be transcribed.This forms the transcription initiation complex and transcription will proceed.
What effect does adrenaline have on heart rate?
Similar to stimulation of sympathetic nerve. But directly effects the sinoatrial node increasing the heart rate to prepare the body for physical demands.
What is the function of the nucleolus?
The nucleolus makes ribosomes
Describe the key features of nervous control
electrical transmission by nerve impulses and chemical transmission at synapse.fast actingusually associated with short term changes eg muscle contraction.action potential carried by neurones with connections to specific cells.response is often very local, such as specific muscle cell or gland.
What is indoleacetic acid (IAA)?
an auxin
What does the cardiovascular control centre detect?
Carbon dioxide and lactate accumulation in the blood, reduction of oxygen and increased temperature.
Give 1 reason why CVS is a better than amniocentesis and 1 reason why its not
Better- Takes place earlier so earlier decision to abort can be made.
Worse- 1-2% chance of miscarriage compared to 1% of amniocentesis.
What effect did IAA and illumination have on plants?
Its role is to stimulate growth and its response is cell elongation.They found that more auxin had passed down the shaded side of the plant when it was illuminated from one side.The reduced concentration on the illuminated side inhibited cell elongation.
What is the function of the mitochondrion?
The site of the aerobic respiration, where ATP is produced. They’re found in large numbers in cells that are very active and require lots of energy.
Draw and describe Spatial summation
Impulses from different synapses, usually from different neurones. The number of different sensory cells stimulated can be reflected in the control of the response.
What does a lysosome do?
Contains digestive enzymes. These are kept separate from the cytoplasm by the surrounding membrane and can be used to digest invading cells or to breakdown worn out components of the cell.
What happens to the skin when it is warm?
Vasodilation
The shunt vessel constricts and muscles in the walls of the arterioles relax.Blood flows through the arterioles making them dilate. More blood flows closer to the surface.More energy is lost.
What is the structure of a strand of DNA and RNA?
polynucleotides composed of mononucleotides linked through condensation reactions.
Why are key hole surgeries helpful to those wanting to participate in sport?
As only a small incision is made the recovery is faster, and it is not uncommon for top athletes to return to normal athletic activities within a few weeks.
What does the capsule of a prokaryotic cell do and what is it made up of?
Made up of secreted slime it helps to protect the bacteria from attack by cells of the immune system.
Which are the first ventricular cells to be depolarised and why?
The ventricular cells at the apex of the heart so the contractions travel upwards.
What are the disadvantages of exercising too little?
Increased risk of obesity, cardiovascular disease (CVD) and diabetes
What is the function of the nucleus
Controls the cells activities (by controlling the transcription of DNA) DNA contains instructions to make proteins. The pores allow substances to move between the nucleus and the cytoplasm.
What is the function of the Golgi apparatus?
It processes and packages new lipids and proteins. It also makes lysosomes.
How can genes be prevented from being transcribed
Protein repressor molecules that bind to DNA of the promoter regionProtein repressor molecules can bind to the transcription factors themselvesThe repressor molecules could be inactive forms of the transcription factors
What bonds holds the bases of the polynucleotides together?
Hydrogen bonds
What are the two nerves connecting the cardiovascular control centre to the heart?
sympathetic nerve and vagus nerve.
How do peptide hormones affect cells?
Peptide hormones are protein chains which are not able to pass through cell membranes easily as they are charged.So instead they bind to a receptor on the cell membrane. This then activates another molecule within the membrane ‘the second messenger’ which brings about chemical changes in the cell.
Why is the arrangement of the DNA double helix the way it is?
The hydrophilic phosphate groups are on the outside of the molecule and the hydrophobic bases lie within the molecule.
What happens to the impulse generated from the SAN?
* The impulse spreads across the right and left atria causing them to contract at the same time.
* The impulse also spreads to the atrioventricular node
* From here the impulse is conducted to the ventricles after about 0.13 second delay.
What are platelet inhibitory drugs? Give a benefit and a risk
Type of anticoagulant, prevent platelets clumping together.
+Treat people who already have blood clots
-Rashes, diarrhoea and excessive bleeding.
How does smoking impact your likelihood to develop CVD?
Carbon monoxide combines with haemoglobin and reduces the amount of oxygen transported in the blood. This reduces the amount of oxygen available to the tissues. If the heart muscles don’t receive enough oxygen it can lead to a stroke.Nicotine in cigarettes makes platelets sticky increasing the chance of blood clots forming.Decreases the amount of antioxidants in the blood, these are important in protecting cells from damage. Fewer antioxidants means cell damage in the artery is more likely.
How is the egg cell specialised for its function?
Follicle cells- form protective coatingZona pellucida- protective glycoprotein layer that sperm have to penetrate.
What are the complementary base pairs in DNA?
A and T, and C and G
What happens when a nerve is stimulated?
If a threshold level due to stimulus is met the voltage dependant Na+ channels open. Na+ flows into axon depolarising the membrane.Voltage dependant Na+ channels close. Voltage dependant K+ channels open. K+ leave the axon repolarising the membrane.The membrane is hyperpolarised. The voltage dependant K+ channels close. K+ diffuse back into the axon to recreate the resting potential.
Occipital lobe
Processing information from the eyes, including vision, colour, shape, recognition and perspective.
How does cell expansion as a result of auxins occur?
The auxins cause the acidification of the cell wall by stimulating the activity of proton pumps that move H+ ions out of the cytoplasm and into the cell wall.The low pH in the cell wall disrupts the bonds that hold the cellulose microfibrils and hemicelluloses together.There is loosening of the cell wall: there is slippage of the polysaccharides relative to each other, bond reform in new locations, allowing bonds to reform in new locations.
What does the flagellum of a prokaryotic cell do and what is it made up of?
Long hair like structure that rotates to make the prokaryotic cell move. Not all prokaryotes have a flagellum. Some have more than one.
What are the 4 lobes of the brain?
Frontal lobeParietal lobeOccipital lobeTemporal lobe
Describe the process of translation of DNA
mRNA attaches to a ribosome and tRNA molecules carry amino acids to the ribosome.A tRNA molecule with an anticodon that’s complementary to the start codon on the mRNA attaches itself to the mRNA by complementary base pairing.A second tRNA molecule attaches itself to the next codon on the mRNA in the same way.The two amino acids attached to the tRNA molecule are then joined together by a peptide bond. The first tRNA molecule moves away, leaving its amino acid behind.The ribosome moves along to the next codon.A third tRNA molecule binds to that codon on the mRNA. Its amino acid binds to the first two and the second tRNA molecule moves away.This process continues, producing a chain of linked amino acids (a polypeptide chain) until there’s a stop codon on the mRNA molecule.The polypeptide chain moves away from the ribosome and translation is complete.
What is the description of the nucleus?
A large organelle surrounded by a nuclear envelope which contains many pores. The nucleus contains chromatin (made from DNA and proteins) and the nucleolus.
Describe the process of how normal lungs regulate mucus water content when there is too little water in the lungs
* Cl- is pumped into the cell across the basal membrane.
* Cl- diffuses through the open CFTR channels.
* Na+ diffuses down the electrical gradient into the mucus.
* Elevated salt concentration in the mucus draws water out of the cell by osmosis.
* Water is drawn into the cell by osmosis.
What is the rough endoplasmic reticulum
A system of membranes enclosing a fluid filled space. The surface is covered with ribosomes.
How do Inhibitory synapses work?
They make it less likely that an action potential will result in the post synaptic cell.
Chloride ions move into the cell carrying a negative charge and potassium ions will move out carrying a positive charge. The result will be greater potential difference across the membrane as the inside becomes more negative than usual (hyperpolarisation). Making subsequent depolarisation less likely. More excitatory synapses will be required to depolarise the membrane.
What are the 4 ethics frameworks
Right and duties max amount of good in world making decisions by self leading a virtuous life
Where are ribosomes found?
Free in the cytoplasm or attached to the endoplasmic reticulum.
how do you calculate cardiac output?
stroke volume x heart rate
What week of pregnancy is CVS tested?
11-14 weeks
Cones
Allow colour vision in bright light but don’t work in dim light.
What week of pregnancy is amniocentesis tested?
15-20 weeks
How does a synapse transmit an impulse?
An action potential arrivesThe membrane depolarises. Ca+ channels open. Ca+ enter the neurone.Ca+ cause the synaptic vesicle containing neurotransmitter to fuse with the presynaptic membraneNeurotransmitter is released into the synaptic cleftNeurotransmitters bind with receptors on the post synaptic membrane. Cation channels open. Na+ flow through the channels.The membrane depolarises and initiates an action potential.When released from the receptor the neurotransmitter will be taken up across the presynaptic membrane (whole or broken down) or it can diffuse away and be broken down.
How do genetics impact your likelihood to develop CVD?
Some people inherit particular alleles that make them more likely to have high blood pressure or high blood cholesterol.
How is habituation achieved?
With repeated stimulation the Ca2+ channels become less responsive so less Ca2+ crosses the presynaptic membrane.Less neurotransmitter is releasedThere is less depolarisation of the postsynaptic membrane so no action potential is triggered in the motor neurone.
Explain the course of events that lead to atherosclerosis
Endothelial disfunction where the endothelium becomes damaged.Inflammatory response occurs where white blood cells move to the damaged area.Plaque formation where white blood cells, lipids and connective tissues form an atheroma.This causes positive feedback as blood pressure rises.
Draw a sensory neurone
* Dendrites
* Axon
* Terminal branches
* Cell body external in between Schwann cells
Where is the hypothalamus?
It lies below the thalamus
Why does vigorous exercise supress the immune system?
The specific immune system is temporarily depressed.
How many hydrogen bonds does A and T have?
2 hydrogen bonds
Draw a Motor neurone
* Dendrites around cell body which is at end of cell
* Axon
* Terminal branches at end
*
What is stroke volume?
the volume of blood pumped out of the left ventricle each time the ventricle contracts
What are antihypertensives? Give a benefit and a risk
Reduces blood pressure.
+Patients can be treated at home
-Can cause abnormal heart rhythms, fainting and headaches
What happens to the skin in order to preserve heat?
Vasoconstriction
The muscles in the arteriole walls contract causing arterioles to constrict.Reducing the blood supply to the surface capillaries. Blood is diverted through the shunt vessel which dilates as more blood flows through it.Blood flows further from the skin so less energy is lost.
How do blood clots cause CVD?
When a coronary artery becomes completely blocked by a blood clot an area of the heart muscle will be completely cut off from its blood supply, so it wont receive any oxygen and wont be able to carry out respiration.
Describe the route of nerve impulses
Receptors detect a stimulus and generate a nerve impulse.Sensory neurones conduct a nerve impulse to the CNS along a sensory pathway.Sensory neurones enter the spinal cord through the dorsal route.Sensory neurone forms a synapse with a relay neurone.Relay neurone forms a synapse with a motor neurone that leaves the spinal cord through the ventral route.Motor neurone carries impulses to an effector which produces a response.
What does a mononucleotide look like?
