21. Which of the following is the best example of a part of the propulsion system of a tractor ? A. Engine
B. Front head light
C. Hood
D. Steering wheel

Which of the following statements is true? a. the main cause for speciation is an increase in gene flow. b. organisms that reproduce asexually are not considered part of a species. c. on a tree of life diagram, speciation is shown by the merging of two different lineages. d.the size of the geographic area inhabited by a population can cause speciation.

Why is earth's outer core hotter than earth’s oceanic crust? earth’s oceanic crust is denser than earth’s outer core is. earth’s oceanic crust has lava flowing from the mantle. earth’s outer core has a composition of solid iron and nickel. earth’s outer core is deeper within earth than oceanic crust is.

Hey everybody i need with a biology question. all the gametes of isogamous organisms are genetically identical. true false