Answer:
Nitrogenous bases contain the genetic information, their amount is variable among different species, and the arrangement of these bases is also variable among different species
Explanation:
Both Watson-Crick and Pauling's DNA models considered that DNA nitrogenous bases (i.e., Adenine, Cytosine, Thymine and Guanine) contain the genetic information that determines the characteristics of living organisms. Moreover, both DNA models also considered that nitrogenous base composition varies between species, as well as the arrangement of these bases in the DNA chain also varies between species. Based on these features, Linus Pauling considered that a model where nitrogenous bases would be arranged on the outside of the DNA molecule would be easier for the DNA molecule to be replicated, transcribed, or repaired. Although incorrect, Pauling's DNA triple helix model was fundamental to develop the helical (double-stranded) structure of DNA, which was finally discovered by Watson and Crick in 1953.
Answer:
mRNA: Carry genetic information from DNA to protein; serve as template for protein synthesis.
tRNA: Serves as adapter molecule and deliver specific amino acid from the cell pool to the mRNA-ribosome complex.
rRNA: Structural component of ribosomes.
Explanation:
There are three types of nongenetic RNAs: mRNA, tRNA, and rRNA.
1. The messenger RNA (mRNA) is formed by the process of transcription in the nucleus. Transcription uses template strand of DNA to specify the nucleotide sequence in mRNA. The mRNA enters cytoplasm to join ribosomes. The nucleotide sequence of mRNA serves as a template and specifies the amino acid sequence of proteins.
2. The transfer RNA (tRNA) serves as an adapter molecule during the process of protein synthesis and binds to the specific amino acids to deliver them to the protein-synthesizing machinery. The anticodon of tRNA binds to the complementary mRNA codons.
3. The ribosomal RNA (rRNA) serves as structural components for ribosomes. Each of the subunits of ribosomes is made up of rRNA and proteins.
Answer:
both could be correct
Explanation:
It usually depends on how fast or how severe the change is, if its mild or happenes slowly over time they may adapt, if it is extreame or happenes very quickly the species could very well die out.
<span>The biological term for such organisms is "deuterostomes". Those who's first opening is the mouth are called protostomes.
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