Why does dna use thymine instead of uracil?

What two fields of study provide the core information that is used to classify organisms?

You and a group of friends are spending your vacation hiking through the mountains. it is cold in the mountains. you will be expending a lot of energy while hiking and you will need plenty of energy to keep you warm. you should pack foods high in to provide the most energy or kilocalories per gram of food. a) carbohydrates b) lipids (fats) c) proteins d) sugars

Earthquakes a.created the rock in arches utah b.can be caused by volcanic eruptions c.are caused by tsunami waves d.wear mountains down into hills