Echinoderms and jellyfish both are radially symmetrical unlike humans which are bilaterally symmetrical but still echinoderms are much more closely related to humans as compared to jellyfish. It is because echinoderms are deuterostomes just like humans which means that their anus is generated from the blastopore. In contrast to this, jellyfish is a protostome which means that its mouth is generated from blastopore. Radial symmetry is an important feature when it comes to comparing animals but being deuterostomes and protostomes is much more important when it comes to estimating evolutionary relationships of organisms.
Messenger RNA (mRNA) molecules carry the coding sequences for protein synthesis and are called transcripts; ribosomal RNA (rRNA) molecules form the core of a cell's ribosomes
Even if remains at constant temperature, while ascending to the surface of the lake Jacques lung pressure will increase if he hold its breath. Thats because the pressure of water weakens and the pre-hold breath in lungs will expand as he rises. This can cause serious lung damage and drowning is possible.
Sympatric speciation is the presence of two species with same surviving ancestral species in the same geographic area. Sympatric species have numerous characteristics that are common in the same geographical area. They have same evolutionary path therefore they are anatomically similar too.
