Genetics and Natural Selection Flashcards
(40 cards)
Chromosomal Abnormality - Trisomy
Having one or more extra chromosomes
e.g. Down’s syndrome, Trisomy 21
Chromosomal Abnormality - Monosomy
Having only one of a pair of chromosomes
Rare in autosomes as embryos with monosomy not viable
e.g. Turner syndrome, on X chromosome (only in females as have another X to compensate)
Genetics - Homozygous
Alleles are the same
Genetics - Heterozygous
Alleles are different
Genetics - Dominant
Only one allele is necessary to produce characteristic
Genetics - Recessive
Both alleles must be the same to produce the characterstic
Genetics - Intermediate
Both alleles equally expressed in heterozygous pairs
Genetics - Autosomal Dominant
If the abnormal genes is inherited, the disorder is present
No carriers
e.g. Huntington’s disease
Genetics - Autosomal Recessive
The abnormal gene must be inherited from both parents in order for the disorder to be present
Carriers
e.g. Phenylketonuria
Genetics - X-Linkage
Genes on the X chromosome are affected so are male-prone disorders
Genetics - Sex-Linkage
Allele is located on the sex chromosomes
e.g. Fragile X Syndrome
Genetics - Sex-linked Dominant
Heterozygous mothers pass onto 1/2 of children
Genetics - Sex-linked Recessive
Both parents would need to pass on same allele
Genetics - Sex-limited
On autosomal chromosomes but triggered by sex hormones
Evolution
Animals and plants are dynamic species
Evolution is gradual and continuous
All organisms come from a common ancestor
Natural Selection
Adapting to a changing environment or maintaining state in a stable environment
Natural Selection - Assumptions
Variation within population
Inheritance of genetics from previous generation
Adaptation to current environment
Studying Genetics - Molecular Genetics
Looks at specific causes of behaviour by locating specific genes associated with behavioural traits
e.g. MAOA-L and violence
Studying Genetics - Molecular Genetics, Singe Gene Disorders
Only one gene is responsible for prevalence of a disorder
Studying Genetics - Molecular Genetics, Single Gene Disorders, Necessary
The effect cannot be present without the cause
Genetic disorders will only occur if a particular mutation is present
e.g. Huntington’s disease can only occur if the specific mutated gene is present
Studying Genetics - Molecular Genetics, Single Gene Disorders, Sufficient
The cause will always result in the effect but the effect can be present if the cause is not present
Genetics disorders will occur if the mutation is present but can also occur as a result of a different cause, in absence of the mutation
e.g. Duchenne’s muscular dystrophy
Studying Genetics - Molecular Genetics, Multiple Gene Disorders
Multiple genes, in combination with the environment and lifestule, produce disorders
Studying Genetics - Molecular Genetics, Multiple Gene Disorders, Gene-Environment Correlation, Passive
Child is the recipient of an environment as a result of the parent’s genetic tendencies which are also inherited
e.g. Parents have ‘musical’ genes and so have instruments in the home and go to concerts, the child is put into this environment where thier inherited genes flourish
Studying Genetics - Molecular Genetics, Multiple Gene Disorders, Gene-Environment Correlation, Active
Child’s genetic tendencies correlate to their environments
e.g. Children inherantly extroverted seek out stimulating environments
