In medusae, mesoglea comprises the bulk of the animal and forms a resilient skeleton. In polyps, the water-filled coelenteron acts as a hydrostatic skeleton, which, in concert with the mesoglea, maintains the form of these animals. Muscles in cnidarians are extensions of the bases of ectodermal and endodermal cells.
Animal Y is an invertebrate, animal Z is a vertebrate
The correct option is A.
Environmental DNA surveillance is used for detection and monitoring of invasive animal species in aquatic and terrestrial ecosystem. The surveillance method provides information for the management personnel about the existence of alien species or outbreak of diseases. Early detection is always crucial in this case in order to prevent fatal consequences.<span />
Ammonoids are good as index fossils because of the following characteristics;
<span>1.
</span>Their abundance and vast distribution across most shallow
marine waters during the periods
<span>2.
</span>They have easily recognizable
features, such as shells and the highly crenulated and complex suture, that are well preserved in rocks
<span>3.
</span>Their rapid
evolution that can assist determine changes and variations in the then environment
Answer
The arm and base of microscope are connected with each other with help of inclination joint. which provide easiness to user during research analysis or other microscopic studies.
It has significant role in light and compound microscope that need light for visualization of examine sample. It also help in easy rotation during focusing toward light for better contrast.
