In this chapter, you will learn to: / understand the effect of inherited factors on human health / understand the effect of environmental factors and lifestyle choices on human health
/ describe the role of biomolecules in a balanced diet / carry out investigations to identify biomolecules in food / describe the negative and beneficial roles micro-organisms play in human health.
Health Health is a person’s physical and mental wellbeing. Human health is affected by: • inherited factors • environmental factors • disease caused by harmful organisms
Inherited factors
In chapter 4, we learned that human characteristics are controlled by genes. Genes are found on chromosomes in the nucleus of the body’s cells. In chapter 5, we learned that mutations (changes) in a gene or chromosome, inherited from one or both parents, can affect a person’s health.
The following table includes examples of health conditions caused by mutations in genes or chromosomes:
Condition Haemophilia Cancer
:Fig. 10.1 Some factors that affect human health Cause
Mutation in the gene for a protein that controls blood clotting
Mutation of a gene that causes cells to divide uncontrollably
Effects
Blood does not clot correctly, causing excess bleeding.
A mass of cells called a tumour forms.
Down syndrome An extra copy of chromosome number 21 Physical and mental development are affected.