O11 Summary

Stage 2 Biology – Organisms Notes

O11. Human beings can control many aspects of their lifestyle.

·         As we age, we learn to make responsible decisions

·         Needs to take into account evidence and consequences of actions

·         Think of yourselves but also friends, family (and foetus if applicable)

·         Australians are not particularly healthy

·         Costs of medical services and hospitals are high

·         High rates of obesity, cancer and heart disease compared to other countries

·         We have free choice about our lifestyle

Diet

·         Access to fast food – processed and has a high proportion of fat, sugar and salt

·         Dietary guidelines: more fibre, less fat, less sugar, less salt, restrict alcohol, drink more water, breast feed babies

·         Supply of vitamins and minerals are important

o   Iron for haemoglobin

o   Calcium and phosphorus for bone development and repair

·         Deficiency diseases if important materials are not present in the blood

o   Iron deficiency – anaemia

o   Vitamin C deficiency – scurvy

o   Poor diet – atherosclerosis and obesity

·         Males and females have different requirements

Exercise

·         Sedentary – only walk when absolutely necessary

·         Benefit of regular exercise – improved muscle tone, less body fat, improved efficiency of heart and blood

·         Need to elevate heart rate for 30 minutes three times a week

·         As a person improves their fitness – resting heart rate declines and it takes less time to recover

·         Poor diet and lifestyle choices cause arteriosclerosis – hardening of the arteries – accumulation of fatty plaque inside the arteries that restricts the blood flow; leads to increased blood pressure; can lead to heart attack or stroke

Drugs

·         Any substance which, when taken into the body, will affect functioning of at least some cells

·         Used in medicine: lower blood pressure, kill bacteria

·         Many legal and harmless drugs when used in moderation – nicotine in cigarettes, caffeine in tea/coffee, ethanol

·         Some drugs can cause medical conditions – chemicals in cigarette smoke and alcohol

·         Many illegal drugs cause serious physical and mental illness, addiction and death (heroin/cocaine)

·         Several hundred thousand addicts in Australia

·         People need to support their habit and can be involved in crime

·         Addiction occurs easily, and then people are unable to make logical and rational choices

·         What is the best way to manage the drugs, the people that produce and sell them and the people addicted?

Ageing

·         Main causes of ageing are the decreased effectiveness of DNA repair enzymes in the nucleus and reduced ability of the nucleolus to manufacture RNA

·         Could be fixed by genetic manipulation