Which of the following is a correct pairing of complementary bases in DNA?

Plants are:

A farmer wants to reduce his need to use insecticides on his corn crop to save money. He plants 80 percent of his field with Bt corn but has to plant the remaining 20 percent with corn that has not been genetically modified. What is the reason for planting only 80 percent of his field with Bt corn if planting 100 percent Bt corn would reduce his need for insecticide even further?

If a crayfish has 200 total chromosomes in its body cells

Which of the two systems listed work together to bring oxygen into your body and deliver it to your cells?

The main product of chemiosmosis is

*It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in its

Aunt Lucy is preparing potato salad for a summer picnic. Unfortunately, when she pulls out the celery, it’s wilted and limp. Lucy’s sister, Carol, tells her to soak the lifeless celery in salt water to revive it. Lucy’s neighbor, Jeannie, tells her to use tap water, and Lucy’s mother, Samantha, pulls out the distilled water from under the bathroom sink. Which solution, if any, will help crisp the celery? Give a biologically relevant reason for your answer.

Pharyngeal slits are present in the embryos of organisms as diverse as fish, chickens, and humans. Why would organisms as different as these have similar embryonic structures?

*A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened?