Why plants don't need specialized respiratory system

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

Afamily has a y-linked disease that affects the father. what is the chance of a male offspring inheriting the same disease? oa. 100% ob. 50% oc. 25% d. 0%

Which of th following best describes how genes produce traits in an organism?