What happened around 500 million years ago?

A chemical bond a. is physically broken. b. holds protons together. c. holds atoms in a molecule together.

DNA and RNA differ in all BUT one of the following ways. A) DNA is double-stranded, while RNA is single stranded. B) RNA uses the sugar ribose in its backbone, while DNA uses deoxyribose.

The plaque (microbial biofilm) that forms between your teeth is a highly anaerobic (oxygen-free) environment, even though the mouth is one of the most aerobic habitats in the body and most of the bacteria living there can use oxygen if it is

How does energy used by an athlete during a game come from energy sunlight

Why is a lake with a clay bottom able to hold more water than a lake with a sand bottom

Which did a large earthquake in Alaska initally cause? which did a large earthquake in Alaska initally cause? A. a volcanic eruption B. flooding C. a landslide D. a tornado

What type of asteroid/meteorite do they believe brought some water to the Earth? a. Stoney Iron b. Iron c. Steel d. Carbonaceous Chondrite

If a cell has 12 chromosomes, how many chromosomes will each of its daughter cells have after mitosis and cytokinesis? and can u explain because i dont understand

A lab technician runs the results of a simple PCR reaction through a gel electrophoresis to test a sample of imported hamburger meat for the presence of a DNA sequence that is known to be found in kangaroos and not in cows.

If Earth was not titted on its axis, what changes would you expect to see in the seasons?