During DNA replication, what is the first process to occur?

a:zipping up of the DNA strand for copying

b:synthesis of the leading strand

c:synthesis of the lagging strand

d:unwinding of the parental DNA by helicase enzyme

According to an American Cancer Society's annual report published in December 2009, the U. S. cancer death rate continues to decline, as it has since the 1990s. This may be attributed to all BUT ONE of these factors.

Some embryos do not survive through to the fetal stage, which begins about two months after fertilization. When this happens, the mother is said to have had A) endometriosis. B) a miscarriage. C) a toxic shock. D) an implantation.

This is the process of separating DNA fragments by size using an electric field and a fluorescent dye.

Which of these nutrition-related diseases is the leading cause of death in the united states?

Which feature is most likely to have been formed by flowing water? A. canyon B. U-shaped valley C. sand dune D. root pry

Which is an advantage of sexual reproduction? a. two parents are required. b. only one parent is required. c. it leads to genetically diverse offspring. d. it leads to genetically identical offspring.

How are three different types of consumers alike and how are they different

What do a door and a venus flytrap leaf have in common

Where would be the best place to find an alpine glacier A) Antarctica B) Greenland C) the Himalayas D) the North Pole

The Sun is A. a very small star. B. a medium-sized star. C. the largest star in the universe. D. the same size as all the other stars.