SFBH: What is a healthy organism?

Question 1

What is health?

Answer 1

A state of complete physical, mental and social wellbeing, and not merely the absence of disease.

Question 2

What is disease?

Answer 2

Any condition that adversely affects the normal functioning of any part of a living thing. E.g. CVD, asthma

Question 3

Problems with definitions of health and disease?

Answer 3

• broad
• concept of health is subjective
• constantly changing on daily basis and depends of life circumstances
• it is possible for someone to be healthy and have disease e.g. heart disease but still healthy
• different to scientific definition

Question 4

Function of genes in maintaining health

Answer 4

• Responsible for maintaining health by regulating cell cycle and limiting growth & reproduction of cells
• Enzymes which control all body processes are proteins and thus have been produced from codes of genes. Genes code for polypeptides.
• Error in gene may result in inability for cells to function.
• Protein metabolism depends on genes.

Question 5

Function of mitosis in maintaining health

Answer 5

• Allows cells in body to function normally as tissues in body are repaired and replaced.

Question 6

Function of cell differentiation & specialisation in maintaining health

Answer 6

• Differentiated cells needed to develop and produce different organs responsible for maintaining health.
• Specialised cells switch on at different times to perform special functions e.g. white blood cells destroy pathogens and clean up blood.

Question 7

Link between gene expression & repair of body cells

Answer 7

Each gene in a cell can be switched on or switched off.
A gene is expressed in DNA when switched on and DNA code is converted into polypeptides that control structure and functions of cells.
If all genes in normal cells are expressed as they should be, the cells function normally & body tissues are maintained and repaired.

Question 8

What is a healthy organism?

Answer 8

• correct functioning of genes
• correct production of genetic material by mitosis
• expression of genes in gene specialisation and differentiation
• healthy cells have regulated cell cycle
• DNA repair genes produce enzymes that ensure DNA is appropriately copied.

Question 9

Gene Expression

Answer 9

• genes control polypeptides
• genes manipulate polypeptides to repair tissues & cells
• genes control whether proteins become cytoplasmic or produce enzymes etc.