What is the main factor that prevents the growth of tropical plants in the northern part of the united states

What is the mrna strand that would be copied from this dna strand

Use the drop-down menu to match the following definitions to the corresponding terms. the total variety of organisms that live in the biosphere a group of organisms that breed and produce offspring that can breed all of the biotic and abiotic factors in an area

To determine if a particular plant is homozygous or heterozygous, you would have to test cross with a