Answer:
Thymine
Explanation:
Uracil is the nitrogenous base present only in RNA, but not in DNA. ... DNA have thymine, guanine, adenine and cytosine. Thymine is replaced by uracil in RNA.
Answer:
DNA coding for rRNA changes relatively slowly
Explanation:
The ribosomal ribonuclei acid( rRNA ) is used for Ribosome synthesis. Ribosomes is the organelle for translation of encoded amino acids in protein synthesis in the cells. The gene that codes for rRNA is called rDNA.Thus must of the functionalities of rDNA are encoded rRNA. Therefore researchers use rRNA for comparison investigations because;
<u>1.The coding region on the rDNA is highly conserved, with low rate of polymorphism, thus rDNA for rRNA transcriptions pathways is relatively slow compare to the one of high rate of polymorphism.</u>
<u />
2. Consequently the conserved region( well preserved amino acid sequence) of the rDNA encoded in rRNA, with low polymorphism, and therefore slow transcription pathways enabled the use of rRNA for investigations of relationship between taxa. Since rRNA is present across all organisms,prokaryotes and eukaryotes the highly conserved coded region of low mutation and therefore slow changes, enable accurate comparison.
The human brain consumes up to 20% of the energy used the entire human body which is any other single organ. the brain represents inly 2%of the body wheight yet it recieves 15% of the cardiac output and 20% of the total body oxygen consumption.
