Paula has studied the effect of ultraviolet light on seed germination. Data were collected on seeds that were exposed to UV radiation and
then allowed to germinate. Which statement is true concerning this
data?
O UV rays help seeds germinate.
O Temperature is insignificant.
There is no control group.
O UV light is toxic to seeds.

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.

In the respiration-photosynthesis cycle shown above, what are the products of cellular respiration that belong in box 2?

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna