In the initiation of muscle fiber contraction, calcium ions bind to tropomyosin, exposing active sites on actin for cross-bridge formation. a. true b. false

What advantage does a crop that undergoes vegetative reproduction have over plants that start from the seed? 1points a they store nutrients. b they can travel farther. c they experience more genetic variation. d they only occur in high-resource environments.

Select the true statements about eubacteria. most live as decomposers and heterotrophs. most only thrive in a narrow range of environments. certain eubacteria are responsible for food poisoning. eubacteria thrive in extreme environments.

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.