What cell organelle contains chromosomes

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

One gene can influence trait(s). one trait can be determined by gene(s).

Which statement correctly describes a way that mutations increase the likelihood that a species will survive in a changing environment