Genetics Flashcards
What is genetics
the biological study of heredity, focusing on how traits are passed from parents to offspring
Who is Gregor Mendel
The founding father of genetics, established key principles of inheritance through his work on pea plants
What are chromosones
Sperm and ovum each carry one set of chromosones, after fertilisation each zygote has 2 sets
What is a gene?
a characteristic at a specific location on a chromosone. A gene is made up of 2 alleles
Explain the types of alleles found in genes
Homozygous (two identical alleles)
Heterozygous (two different alleles)
What does phenotype mean?
An observable trait e.g. being right handed
What is gene mutation
a spontaneous change in a gene or chromosome often occurring during cell division
mutations in body cells have limited impact
mutations in gametes affect all cells in the offspring
chromosome mutations can result in serious conditions due to incorrect numbers or structure
What is Down’s Syndrome
Condition caused by an extra chromosome on the 21st pair leading to development delays and specific physical traits
What is phenylketonuria (PKU)
recessive disorder preventing the breakdown of phenylalanine; can be treated with a specialised diet
What is sickle cell anaemia
recessive disorder causing defective red blood cells, fatigue and pain are symptoms
What is cystic fibrosis
recessive disorder resulting in thick mucus and digestion issues, treated with physiotherapy and medcations
What is Huntington’s disease
Dominant disorder with a late onset, causing brain damage and motor difficulties
What are 2 types of genetic testing
Chorionic Villus Sampling (CVS) - tests cells from the placenta for disorders in early pregnancy but can result in miscarriage
Amniocentesis - tests amniotic fluid for conditions, performed later in pregnancy and lower risk than CVS
