Patterns of Inheritance Flashcards
(16 cards)
What are the genetic and environmental factors affecting phenotypic variation?
Phenotype is affected by genotype and environmental factors like nutrition and
light
How does sexual reproduction lead to genetic variation?
Meiosis introduces variation via crossing over and independent assortment;
fertilisation is random.
What are the patterns of inheritance in monogenic crosses?
Inheritance of single gene traits following Mendelian ratios.
What are the patterns of inheritance in dihybrid crosses?
Inheritance of two genes showing independent assortment or linkage
What are multiple alleles?
Traits determined by more than two alleles e.g. blood groups.
What is sex linkage?
Genes located on sex chromosomes affecting inheritance patterns
What is codominance?
Both alleles expressed equally in the phenotype.
What is epistasis?
One gene masks the expression of another.
What is autosomal linkage?
Linked genes inherited together on the same autosome.
How is a chi-squared test used in genetics?
Statistical test to compare observed and expected ratios.
What is the genetic basis of continuous and discontinuous variation?
Continuous = polygenic, affected by many genes. Discontinuous = monogenic,
clear categories.
What factors affect evolution in a species?
Stabilising and directional selection, genetic drift, bottlenecks, founder effect.
What factors affect evolution in a species?
Used to calculate allele/genotype frequencies assuming no evolution.
What is the role of isolating mechanisms in speciation?
Geographical or reproductive isolation leads to speciation.
What is artificial selection?
Human-controlled breeding for desirable traits in plants or animals.
What are the ethical issues with artificial selection?
Reduces genetic diversity and may cause suffering in overbred animals
