Genetic Factors Flashcards
What are genes?
Sets of instructions to cells that determine growth and development. Individuals inherit 23 pairs of chromosomes from each parent, which contain genes.
How can health conditions arise from genes?
Health conditions can arise from defective inherited genes.
What is a dominant gene?
A gene that only needs to be passed on from one parent for the child to develop a condition.
What are two examples of conditions caused by dominant genes?
- Brittle bone disease: Causes bones to break easily.
- Huntington’s disease: Causes involuntary movement, cognitive, and psychiatric disorders.
What is a recessive gene?
A gene that must be passed on from both parents for the child to develop the condition.
What are three examples of conditions caused by recessive genes?
- Cystic fibrosis: Causes a build-up of thick, sticky mucus that can damage the lungs.
- Phenylketonuria (PKU): Causes intellectual disability and developmental delay.
- Duchenne muscular dystrophy: Causes muscle weakness and difficulty with motor skills and walking.
What happens if a defective gene is passed on from one parent only?
The child becomes a carrier.
What is Down’s syndrome?
A condition where individuals have an extra copy of chromosome 21, causing characteristic facial features, growth delay, and intellectual disability.
What is Klinefelter syndrome?
A condition where males have an extra X chromosome, causing problems during or a delay in puberty.
What is colour-blindness?
A condition caused by mutations in the chromosome, making it difficult to distinguish colours. It is more common in males.
What is genetic susceptibility to disease?
An increased likelihood of developing a disease because of an individual’s genetic makeup.
What diseases can genetic susceptibility lead to?
• Cancer.
• High blood cholesterol.
• Diabetes.
What other factors can affect the likelihood of developing diseases?
• Environmental factors.
• Lifestyle.
• Life events.
• Availability of preventative treatment.
