Within a DNA molecule, which nitrogen base pairs with cytosine (C)?
A. uracil (U)
B. thymine (T)
C. adenine (A)
D. guanine (G)

What is the difference between bacterial infections and viral infections?

Grade 91.)the gravitational pull from the moon words).2.) what is the rate of gravitational 3.)if you drop a hammer, is it more likely to drop handle side down, head side down, or equal chance that it will land either way? why? 4.)a car moves 60km east and 90km west.a.) what is the distance the car traveled? b.) what is the car's displacement5.)what is the average velocity of a car that moved 60 km south in 3 hours? 6.) a car starts from rest and acceleration to 60 m/s over a time of 5 seconds. what is the acceleration of the car? 7.)what is the speed of an object at rest?

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?