Biology: Non-infectious diseases

• Why do fat-tailed dunnarts go into torpor in hot weather?

  Thermoregulation: They can lower their body temperature through decreasing their metabolic rate
• Describe and provide examples of genetic engineering:

  Description: Manipulation of DNA to prevent disease

  Examples: Golden rice to reduce Vitamin A Deficiency
• Describe the function of the auditory canal:

  Directs sound waves into the eardrum
• Define active transport:

  Active transport is against the concentration gradient and requires an input of energy
• Identify two reasons why melanoma rates increase with age?


  More exposure to the sun

  Cancer takes a long time to form

  Weaker immune systems
• Define homeostasis

  The maintenance of a relatively constant internal composition
• What is the function of a receptor in homeostasis?

  Detects in the change
• Why do some people choose not to get cochlear implants?

  They don't work very well in adults

  Accessibility issues

  Some people don't want implants

  Costly
• Outline the importance of epidemiological studies:

  To help find the origin of the disease and thus make it easier to come up with treatment plans, prevention and how to control the disease so it doesn't progress further
• For the first 4 days of its life, gas exchange occurs across the skin of the baby fat-tailed dunnart. How can this be possible?


  Thin skin and high surface area to volume ratio allow for gas exchange through diffusion, it therefore doesn't need to use it's lungs
• Describe why the incidence and prevalence of scurvy is so common in low income families?

  Poor nutrition and lack of access to fresh fruits and vegetables. Additionally, fresh fruit and vegetables are expensive.
• Why do fat-tailed dunnarts have thick fur?

  To retain their body heat
• Relay the steps of how a bone conduction implant works

  A microphone detects the sound

  Sound processor converts the soundwaves into vibrations

  The vibrations pass through the implant into the ear

  The cochlear detects the vibrations

  The vibrations are then converted into electrochemical impulses

  The electrochemical impulses travel to the brain via the auditory nerve

  The soundwaves then reach the brain
• Define 'adaptation':


  The process of change by which an organism or species becomes better suited to its environment
• Which internal condition in a mammal is controlled by the endocrine system?

  The concentration of glucose in the blood
• What is the purpose of the counter current system in kidney dialysis?

  Increased rate of diffusion from the blood into the dialysis fluid. Efficient removal of waste products and reabsorption of essential substances.
• What parts of the ear are in the 'outer ear'?

  Pinna and ear/auditory canal.
• Define refraction:

  The bending of light as it passes from one transparent substance into another
• What is the function of the auditory nerve?

  To transmit nerve impulses to the brain
• Predict what will happen if our kidneys stopped reabsorbing?

  Excessive loss of water and essential nutrients i.e., your body won't get enough glucose (for respiration), amino acids, ions or water which will eventually kill you
• Where does passive transport occur in the kidney verses kidney dialysis?

  In the kidney: Everywhere

  In articificial dialysis: The dialysis tubing
• What is cancer?

  Cancer is a disease characterized by the uncontrolled growth and spread of abnormal cells in the body as a result of a mutation in the cells. It can also result in the suppression of apoptosis (programmed cell death).
• Define passive transport:

  Passive transport goes with the concentration gradient and does not require an input of energy
• Account for why data for prevalence/incidence is given in rates, not total numbers?

  Rates are used to account for differences in population size and allow for meaningful comparisons between different populations or time periods. Total numbers alone do not provide a standardized measure of disease occurrence.
• Define non-infectious disease:

  A disease cause by a factor other than a pathogen, including genetic, nutritional and environmental factors
• In the nephron, what happens to the glucose, amino acids, water and ions?

  All of the glucose and aminoacids are reabsorbed back into the blood while the water and ions are balanced

  Our body needs glucose for respiration and amino acids for making proteins
• Explain why there are changes in the distribution of West Nile fever over time:

  The virus is carried by mosquitoes, so if a person has gotten West Nile fever in America and then travels to France, a mosquito can bite them in France and transfer the disease to other people there.

  Crows are migrating, carrying the disease.
• Evaluate the success of the Slip Slop Slap Seek Slide programme in preventing skin cancer:

  Cases have fallen from 25/100 000 people among those aged 20 to 24 who have been exposed to the campaign since birth

  Data also shows a fall in the most common skin cancers in people aged up to 25

  This shows that a valid prevention method is educating people to make better choices
• Under what circumstances would someone require kidney dialysis?

  Kidney failure or end-stage renal disease.
• What is the cochlear?


  The cochlea is a spiral-shaped, fluid-filled structure in the inner ear that is lined with thousands of tiny hairs called stereocilia that are responsible for detecting pressure waves (sound vibrations) and conveting into electrical signals that can be interpreted by the brain.
• What is myopia?

  Also called near-sightedness, it is when a person can see close up but not far away due to their eyeball being too long OR their cornea being too curved causing the image to be focused in front of the retina.
• Account for the benefit of cyclosprine over drugs that suppress the whole immune system:

  Cyclosporine is an immunosuppressent drug that only suppresses lymphocytes, this means that the rest of the immune system is able to fight off pathogens. A drug that suppresses the whole immune system leaves the body without any antibodies to fight off viruses and other disease-causing organisms.
• Account for why 'control' is not relevant for non-infectious diseases:

  Control is methods to reduce/stop the spread of pathogens. Non-infectious diseases are not caused by pathogens.
• Compare and contrast rods and cones:

  Rods:

  Detect black, white, grey and movement

  Work at night

  Contain rhodopsin

  Cylindrical shaped

  Found on the outside of the retina

  Cones:

  Detect red, green and blue

  Don't work at night

  Contain photopsin

  Conical shaped

  Found in the centre of the retina

  Similarities:

  Both are found in the eyeball

  Both are found in the retina

  Both work during the day
• What is the role of the nervous system in thermoregulation?

  Receptors: Thermoreceptors in the hypothalamus and the skin

  Transmits messages

  Blood vessel constriction and dilation

  Sweat glands

  Hair on limbs
• Evaluate the benefits in genetic counselling in preventing genetically inherited diseases:

  If you are able to detect the disease, you are able to find ways to prevent it

  If we can, we should
• Is all reabsorption active? Justify your answer.

  No, it is active (glucose and ions) AND passive (water)
• Which internal conditions in mammals are controlled by both the endocrine system and the nervous system?

  Body temperature

  Response to stress

  The concentration of salts and water in the blood and tissues
• What are the advantages and disadvantages of a bone conduction implant?

  Advantages:

  Higher quality than a cochlear implant

  Can detect more frequencies

  Good for people with absent or malformed ears where hearing aids don't fit properly

  Disadvantages

  Surgery is done via general aesthetic

  Possible complications due to surgery

  Risk that the new bone around the implant will fail and the implant might fall out

  Any head trauma can cause much more serious consequences

  It's a costly procedure, around $10 000

  The cochlear and auditory nerve must work
• How would the authorities prevent scurvy outbreaks in refugee camps?

  Give them vitamin C, either fruit or juice