Why do viruses need living hosts, such as bacteria or eukaryote cells? a) the host cell is the source of food for the virus. b) viruses depend on the host cells that they infect to reproduce. eliminate c) viruses lack cell structure and cannot survive without a host cell. d) viruses depend on a host cell because they lack their own dna or rna.

Can you identify which of the following groups of organisms are, or are not, populations? a. the american bison (bison bison) and grey wolves (canis lupus) currently living in yellowstone national parkb. all of the rainbow trout (oncorhynchus mykiss that) that have ever lived in lake eriec. the group of american bison (bison bison) currently living in yellowstone national parkd. a group of calliope hummingbirds (selasphorus calliope) and a group of rufous hummingbirds (selasphorus rufus) living in the same new hampshire woodse. the northern cardinals (cardinalis cardinalis) living on opposite shores of lake champlain f. all of the whales currently living in the atlantic ocean off cape cod, massachusetts

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

1. fold your hands together so your thumbs cross over ,and look at your thumbs. which thumb feels most "comfortable" on top is actually controlled by a gene. the left thumb folding over the right thumb is a domi