3what structural problem prevents adenine from pairing with guanine?
the bases are both short.
they lack phosphate groups.
they lack the deoxyribose group.
the bases are both long.

4. rosalind franklin contributed to the understanding of dna by

producing images of dna molecules using x-rays.
figuring out that dna strands form a double helix.
conducting experiments that showed which nucleotides are

This is one of the five kingdoms in the older biological succession. organisms in this kingdom are prokaryotic

Need the diagram below, which is not drawn to scale, shows the position of the earth, moon, and sun. what type of eclipse occurs when the earth, moon, and sun are lined up in the order shown? a. planetary eclipse b. solar eclipse c. martian eclipse d. lunar eclipse

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.