How would muscle contractions be affected if skeletal muscle fibers did not have T-tubules?

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. assume all are homozygous. chinchilla x albino a) all chinchilla b) 1/2 chinchilla, 1/2 albino c) 3/4 chinchilla, 1/4 albino

When plants use sunlight to make food, the energy of sunlight is