. Which of the following investigations would be most helpful in allowing students to investigate the process of convection?

A. Students will crack open eggs on the sidewalk outside of their school at various times during the day. Students observe the changes in the egg color over a time of 5 minutes.

B. Students place yellow hot water on one side of a container and blue cold water on the other. Students then release a divider that separates the two sides and observe how the two types of water mix.

C. Students will place rods made of various materials on hot plates. Students place one end of the rod on the hot plate and record the temperature of the other end of the rod over a period of three minutes.

D. Students place digital thermometers at various distances from a heat lamp. Students then record the temperature of the air at each distance on their data table.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.