The periodic table is organized into vertical groups of

A

elements with similar properties.

B

compounds with different properties.

C

elements with all the same chemical properties.

D

compounds with all different physical properties.

The minimum amount of energy necessary for a chemical reaction to begin?

How does ATP power a chemical reaction? A. Molecules of ATP are converted back to ADP, releasing the energy stored in their phosphate bonds. B. Each molecule of ATP breaks down into three phosphate molecules, releasing energy from phosphate bonds. C.

Which system ensures the transmission of genetic information from generation to generation? A. nervous B. reproductive C. immune D. circulatory

Which agent of erosion is mainly responsible for the formation of the grand canyon

Is the study of the interactions among living things, and between living things and their enviornment

What is the period during the cardiac cycle when the ventricles are completely closed and blood volume in them remains constant as the ventricles contract?

Forest elephants in Africa have been confirmed as a different species from the larger savanna elephant seen here. Scientists believe the savanna elephant is as different from the forest elephant as Asian elephants are from woolly mammoths.

What competitive processes or forces are ever-present during a star's lifetime?

Which occurs during transcription? A. DNA is copied to create a second DNA strand. B. mRNA codons and tRNA anticodons assemble amino acids. C. DNA is unzipped with the aid of DNA polymerase. D. mRNA is synthesized from a strand of DNA.

In a beach ecosystem, what can limit growth of organisms? A. ocean and rocks B. oxygen C. abundant food source D. moderate temperatures