Patterns Of Inheritence Flashcards
What is a phenotype?
Visible characteristics of an organism
What is a genotype?
The genetic makeup of an organism
What are the different types of chromosome mutations?
Deletion Inversion Translocation Duplication Non- disjunction
What does deletion involve?
Part of a chromosome, containing genetic material is lost.
What does inversion involve?
A section of chromosome breaks of. Turns 180 degrees and joins again. Some genes are too far from the regulatory sequence to be expressed.
What does translocation involve?
A section of a chromosome breaks off and joins another chromosome.
What does duplication involve?
A piece of chromosome may be duplicated- overexpression
Why is overexpression bad?
Too many of certain l proteins or gene regulating nucleic acids may disrupt metabolism
What does non- disjunction involve?
A pair of chromosomes fail to separate, leaving one gamete with an extra chromosome- e.g. Down syndrome
What is a genotype?
The genetic makeup of an organism
What is a phenotype?
The visible characteristic of an organism
Heterozygous?
Having different alleles on a gene locus on a pair of homologous chromosomes
Homozygous?
Having identical alleles on a gene locus on a pair of homologous chromosomes
Monogenic?
Determined by a single gene
Why is dihybrid?
Involving two gene loci
Sex linked?
Gene present on the sex chromosome
What is codominant?
Where both alleles present in the genotype of a heterozygous individual contribute to the individual’s phonotype
What is autosomal linkage?
Gene lock present on the same autosome (non-sex) that are inherited together
What is epistasis?
Interaction of non-linked loci where once masks the expression of another
Directional selection?
A type of natural selection that occurs when an environmental change favours an new phenotype which results in a change in the average population
What is the founder effect?
A small sample of an original population establishes in a new area, its gene pool is. It as diverse as that of the parent population
What is a genetic bottleneck?
A sharp decline in population size due to environmental catastrophes. This reduces the genetic diversity.
What is stabilising selection?
Natural selected leading to constancy in a population. Intermediate phenotypes are favoured and extreme phenotypes selected against. Reduces genetic variation.
What is a population?
Members of a species, living in the same place at the same time. Can interbreed.
