inheritance Flashcards
what is variation?
the differences that exist between members of the same species
what are the two types of variation?
continuous and discrete
what is discrete variation?
a characteristic that can divide a species into two or more DISTINCT groups
what are some examples of discrete variation?
ability to roll the tongue, blood group
what is single gene inheritance?
a characteristic controlled by only one gene
what is continuous variation?
a characteristic that varies amongst a species in a smooth, continuous way from one extreme to the other and does NOT fall into distinct groups
when a characteristic is controlled by the alleles of several genes, what does this result in?
the characteristic being expressed as a range of phenotypes eg human height
what is the name given to a characteristic controlled by more than one gene?
polygenic inheritance
what are examples of continuous variation?
body mass (humans), hand span (human), milk yield (cows)
define gene.
a unit of inheritance
define allele.
the form of a gene
define phenotype
the physical characteristics of an organism
define genotype
the alleles present in the organism
define dominant
the allele of the gene that is always shown if present
define recessive
the allele of the gene that is masked by the dominant allele
