Answer:
In normal conditions, introns serve following functions in the body of an organism:
1) They contain genes of miRNA which are known as Mirtrons, reverse transcriptase, endonucleases, transposase etc.
2) It is because of presence of introns that alternative splicing of mRNA is possible. The sex determination in drosophila is based on alternative splicing.
Apart from this, alternative splicing can be useful and beneficial in an unforeseen situation such as an environmental problem which is faced by the organism for the first time.
Explanation:
Alternative splicing is an important mechanism because with the help of alternative splicing different type of proteins can be synthesized from the same pre mRNA transcript. In case suddenly the surrounding environment of an organism is changed and the environmental conditions have become extremely harsh due to which organism's life is at stake, in such situation organism may make a different type of protein through alternative splicing which can help the organism in survival.
Default splicing in Drosophila leads to the development of male off-spring while female off-spring is produced as a result of alternative splicing.
<span>Answer: “Comparing the mitochondrial DNA between different eukaryotes to see how closely they are related.”</span>
The endosymbiotic theory focuses on the origin of two eukaryotic organelles that have bacteria characteristics (mitochondria in animals and chloroplasts in plants). These two are s are believed to have developed from symbiotic bacteria.
<span>In designing an experiment that would support the endosymbiotic theory, the statement that would provide the best evidence is comparing mitochondrial DNA between different eukaryotes to see how closely they are related.</span>
B - They have different arrangements of atoms.
