A muscle cell contracts or expands when . A. actin and myosin filaments slide over each other B. axons transmit signals to chloroplasts C. xylem and phloem open and close D. cilia project outward from the cytoplasm

Afisherman is dragging his boat from the shore out into the ocean. match the following lists of areas he will move over in the correct order. continental rise continental slope continental shelf [tex]1.[/tex] [tex]2.[/tex] [tex]3.[/tex]

Biology ! the conversion of inorganic carbon to organic carbon by plants during photosynthesis is known as _[blank]_. filtration immigration reabsorption primary production

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.