Which is not true of selective breeding? Selective breeding always produces unhealthy
offspring
Selective breeding can be used to weed out weak
genes.
Selective breeding can be used to pass on
desirable genes.
Selective breeding has been used by humans for
thousands of years.

selective breeding always produces unhealthy offspring

Explanation:

false becasue its mostly healthy and dominant genes

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.