How is energy passed from one trophic level to the next?
i. food
ii. light
iii. heat
i only i only
b. i and ii only
c. ii and iii only
d. i, ii and iii

Multicellular organisms use cell division, mitosis, for growth and the maintenance and repair of cells and tissues. single-celled organisms may use cell division as their method of reproduction. regardless of the reason for mitosis, the process ensures genetic continuity. what is the step in the cell cycle that ensure genetic continuity?

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.

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.