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.
Allopatric speciation?
Formation of 2 different species from one original species due to geographical isolation.
Sympatric speciation?
Formation of 2 species due to reproductive isolation
Artificial selection?
Selective breeding of organisms involves humans choosing the desired phenotypes and interbreeding those phenotypes
DNA sequencing?
A technique that allows genes to be isolated and read
DNA ligase?
Enzymes that catalyses the joining of sugar and phosphate groups within DNA
Germ line therapy?
Gene therapy by inserting functional alleles into gametes or zygotes
Somatic cell gene therapy?
Gene therapy by inserting functional alleles into body cells
