Question

define mass selection and pure-line selection with examples for each.

Answer 1

Pure line selection-Uniform strain of organisms that're considered pure genetically & arise out of continuous inbreeding & artificial selection.
Mass selection-It's mixed strain of organisms that aren't pure & are mixture developed from more than one pureline.
1)Varieties aren't mixtures & are developed as pureline in pureline selection.Variety is mixture of purelines in mass selection.
2)Pureline involves scientific procedures & isn't practised by farmers.Mass selection is practised by farmers unknowingly.