When a scientific experiment is carried out in a controlled setting, all variables are kept the same except for the variable.
a. environmental
b. observational
c. experimental
d. control

Fossils can only be formed when? if mud, silt or tar is in the area to preserve the fossil ierosion does not occur and allows the fossil to form oxygen and microorganisms cannot decay the bones the area is dry and does not contain mud or silt

Match the pollutants. 1. a chlorofluorocarbon smoke 2. a biodegradable organophosphate insecticide freon 3. particle pollution paint 4. hazardous waste monoxide 5. carbon is completely burned malathion 6. carbon is incompletely burned dioxide

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.