Nearly all life on Earth ultimately gets its energy from the sun, which gets "its"energy through nuclear fusion. <span>With the exception of hydrogen, all of the chemical elements needed for life were produced by nuclear fusion of lighter elements, either in the cores of stars or in the shock waves of supernova explosions.</span>
the ability to reproduce.
Homologous structures are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in the descendants. They all have the same basic pattern of bones. They inherited this pattern from a common ancestor. However, their forelimbs now have different functions
The following is correctly matched with its tissue system is -
4) stele/vascular tissue system
Stele is the the central core/cylinder of the stem and root of a vascular plant, consisting of the xylem and phloem and other supporting tissues. Vascular plants include clubmosses, horsetails, ferns, gymnosperms etc.
Answer:
A) many noncoding stretches of nucleotides are present in mRNA.
Explanation:
A transcription unit in eukaryotes includes the region that code for mRNA extending from the 5' cap site to the 3' poly-A site. It also includes the controlling regions. The mRNA formed by transcription also has some non-coding intervening sequences. These are called introns. Introns are removed from the primary transcripts by the process of splicing that occurs after transcription.
Therefore, a transcription unit that is 8,000 nucleotides long may use only 1,200 nucleotides to code for a protein having 400 amino acids since the rest of the nucleotides are part of introns and are removed from mRNA after transcription.
