What two things are present in plant cells but never in animal cells

The polio virus can cause skeletal muscle paralysis by destroying neuron cell bodies. what area of the spinal cord is destroyed

Read this summary of a scientific theory: "cells are the most basic structural and functional units of life. all living organisms are made up of one or more cells. all cells that are alive in the world today came from pre-existing cells." which of the following would require this theory to be modified? -a.) a survey finds that a majority of people believe viruses carry out the basic processes of life. -b.) a prominent scientist says she feels strongly that one day the theory will be challenged by life on other planets. -c.) the dna of unicellular and multi-cellular organisms is shown to have many fundamental similarities. -d.) scientific observations show that microscopic organisms living in the deep ocean are not made up of cells.

Visualize the structural formula of each of the following hydrocarbons. which hydrocarbon has a double bond in its carbon skeleton?