Experiments using "optical tweezers" measure the elasticity of individual dna molecules. for small enough changes in length, the elasticity has the same form as that of a spring. a dna molecule is anchored at one end, then a force of 1.5nn (1.5×10−9n) pulls on the other end, causing the molecule to stretch by 5.0nm (5.0×10−9m).

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

Astudent reads the following text in a science book: scientific evidence tells us that the cause of earths four seasons is the tilt of earth as it revolves around the sound the student is instructed to illustrate this information in a science book. how will the student illustrate winter in the northern hemisphere? a.earths northern hemisphere will tilt away from the sun. b. earths northern hemisphere will tilt toward the sun. c.earths orbit will be farther away than from the sun d. earths southern hemisphere will tilt away from the sun.

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time