Principles Of Inheritance Flashcards
Which Austrian monk carried out experiments using peas?
Gregor Mendel.
Define character.
Heritable feature.
Define trait.
Variant for a character.
Define phenotype.
Organisms traits.
Define genotype.
Genetic makeup.
Define F1.
First set of offspring.
Define F2.
Second set of offspring.
What is Mendel’s first law?
The two members of a gene pair segregate from each other in meiosis; each gamete has an equal probability of obtaining either member of the gene pair.
What is Mendel’s second law?
The law of independent assortment; unlinked or distantly linked segregating gene pairs assort independently at meiosis.
Who recognised that Mendel’s experiment reflects the behaviour of chromosomes during meiosis?
Sutton and Boveri.
The existence of genes can be inferred by observing what?
Standard progeny ratios in the descendants of matings between different phenotypes.
Discrete phenotypic difference in a character is often determined by what?
A difference in a single gene.
Define autosome.
A chromosome that is not an sex chromosome.
Define lethal allele (homozygous lethals).
Alleles that cause an organism to die only when present in homozygous condition.
Define penetrance.
The percentage of individuals with a given genotype who exhibit the phenotype associated with that genotype.
Define 100% penetrant.
Genotype always shows phenotype.
Define expressivity.
Degree to which a particular genotype is expressed in the phenotype.
Define complete penetrance.
Identical known genotypes yield 100% expected phenotype.
Define constant expressivity.
Identical known genotypes with no expressivity effect yield 100% expected phenotype.
Define incomplete penetrance with variable expressivity.
Identical known genotypes produce a broad range of phenotypes due to varying degrees of gene activation and expression.
Define incomplete penetrance.
Identical known genotypes yield less than 100% expected phenotype.
Define variable expressivity.
Identical known genotypes with an expressivity effect yield a range of phenotypes.
Who carried out the experiment of inheritance in sweet peas involving flower colour?
Bateson and Punnett.
Define propositus.
A member of a family who first comes to the attention of a geneticist.
