What is the relationship between perihelion/aphelion and the seasons?

Which taxon group is more specific, in regards to organisms that are in that group? mammalia animalia

What role do traits play in affecting an organisms ability to reproduce? finches

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents