Lecture Week 2

Question 1

Contemporary Nature v Nurture approach

Answer 1

• There is an interaction between heredity and environment
• Heredity creates dispositions
• Dispositions Interact with envorinmental influence

Question 2

Nature v Nurture in the Pre Natal Stage

Answer 2

• There are aspects of this debate already occuring in the pre natal stage
• Development is biologically determeined (Nature)
• Teratogens affect the environment in the womb (Nurture)

Question 3

Depth Perception Acquisition

Answer 3

• The acquiring of the visual ability to perceive the world in three dimensions (3D) and the distance of an object
• Achieved when the brain processes different pictures from each eye and combines them to form a single 3D image.
• Makes it possible for the eyes to determine distances between objects and to tell if something is near to us or far away.
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Question 4

Evolutionary Theory of Aging

Answer 4

• Survival through reproduction
• Natural Selection does not eliminate harmful conditions that appear in older age
• Evolutionary benefits decrease with age
• Natural Selection linked to reproductive fitness so conditions affecting aging are not selected out

Question 5

Cellular Clock Theory

Answer 5

• Hayflick (1977) - cells divide 75-80 times
• Cells can only divide a certain number of times
• Once they become less capable of dividing they become less able to survive
• This all depends on Telomeres that cap chromosomes at DNA level
• Each time cells divide the Telomeres become shorter

Question 6

Telomeres

Answer 6

• Caps on DNA Chromosomes
• Each time a cell splits the Telomeres get shorter and shorter until it can’t divide anymore

Question 7

Free Radical Theory

Answer 7

• When cells metabolise energy they produce a byproduct
• This byproduct includes free radicals

Question 8

Free Radicals

Answer 8

• Oxygen in the body splits into single atoms with unpaired electrons.
• Electrons like to be in pairs, so these atoms, called free radicals, scavenge the body to seek out other electrons so they can become a pair.
• Unstable molecules with unpaired electrons
• Unavoidable byproduct of cellular metabolism.
• Can steal electrons from lipids, proteins, RNA, and DNA, causing them damage

Question 9

Mitochondrial Theory

Answer 9

• Decay in Mitochondria leads to ageing
• could be caused by Oxidative damage from Free Radicals
• Loss of nutrients supplied by the cell
• Defects in Mitochondria connected to:
  
  • Cardiovascular Disease
  • Neurodegenerative disease; Parkinson’s & Dementia
  • Decline in Liver Function
• Does Mitochondrial damage cause ageing or does ageing accompany Mitochondrial damage? Not Known
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Question 10

Hormonal Stress Theory

Answer 10

• When stressed individuals experience stress the body releases hormones:
  
  • adrenaline: epinephrine & norepinephrine
  • Corticosteriods: cortisol
• These hormones stay in the body for longer then when younger
• Problematic because this impedes the body’s ability to self regulate