Like DNA, RNA contains four nitrogenous bases. Three of them are the same as those found in DNA. The one that is different is called .
The five-carbon sugar in RNA is called .

During the process of meiosis, special cells called gametes are formed. gametes only have half the number of chromosomes that the other cells in the body have. what form of reproduction do organisms that produce gametes use?

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.

Which of the following types of reactions would decrease the entropy within a cell? a. dehydration reaction, b. hydrolysis, c. respiration, d. digestion, e. catabolism.