Which of the following pairs with uracil in rna? adenine thymine guanine cytosine rna is single stranded and found mainly in the nucleus. true false which of the following is not true? dna is found in the nucleus. dna replication produces four new strands of dna. dna and rna each contain four nitrogenous bases. a nucleotide consists of a sugar, a base, and a phosphate.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.