The researchers analyzed 962 polychaete species sampled from 68 field sites worldwide, each from a low-oxygen setting below 150 m water depth. List one or more variables that the researchers likely were trying to control by collecting so many data points

the glands which are associated with each description is given below:

answer: grassland biomes are closer to the equator and receive more rain.

grasslands are biomes that are dominated by grasses rather shrubs and trees. savanna are biomes that exhibit grasses, shrubs and small tree as vegetation. grasslands are located near the equator of the earth. these are found in north america. savanna biomes are found in africa, south america, australia and india. grassland exhibit moderate climatic conditions, it receives   amount of rainfall higher than savanna.   therefore, savanna exhibit dry and hot climatic conditions.

yo

c is the correct answer!