when dna makes rna uridine is the base that replaces thymine.
when dna makes rna uridine is the base that replaces thymine.
when dna makes rna what is the base that replaces thymine?
uridine
in rna, uracil base-pairs with adenine and replaces thymine during dna transcription. methylation of uracil produces thymine. in dna, the evolutionary substitution of thymine for uracil may have increased dna stability and improved the efficiency of dna replication (discussed below). uracil pairs with adenine through hydrogen bonding. when base pairing with adenine, uracil acts as both a hydrogen bond acceptor and a hydrogen bond donor. in rna, uracil binds with a ribose sugar to form the ribonucleoside uridine. when a phosphate attaches to uridine, uridine 5'-monophosphate is produced.
uracil
the molecular basis of dominance was unknown to mendel. it is now understood that a gene locus includes a long series (hundreds to thousands) of bases or nucleotides of deoxyribonucleic acid (dna) at a particular point on a chromosome. the central dogma of molecular biology states that ""dna makes rna makes protein"", that is, that dna is transcribed to make an rna copy, and rna is translated to make a protein. in this process, different alleles at a locus may or may not be transcribed, and if transcribed may be translated to slightly different versions of the same protein (called isoforms). proteins often function as enzymes that catalyze chemical reactions in the cell, which directly or indirectly produce phenotypes. in any diploid organism, the dna sequences of the two alleles present at any gene locus may be identical (homozygous) or different (heterozygous). even if the gene locus is heterozygous at the level of the dna sequence, the proteins made by each allele may be identical. in the absence of any difference between the protein products, neither allele can be said to be dominant (see "co-dominance", above). even if the two protein products are slightly different (allozymes), it is likely that they produce the same phenotype with respect to enzyme action, and again neither allele can be said to be dominant.
dominance (genetics)