Echinoderms evolved from bilateral ancestors and they are bilateral in their free swimming juvenile life stage. As adults they assume a pentamerous or radial symmetry by metamorphosis of juvenile to adult form.
Answer: it would be b. a biologist studying insects.
Answer:
Atoms make up every substance around you.
You cannot see single atoms without a special microscope. But every substance around you is made of atoms.
Explanation:
A gastrovascular cavity is a digestive sac with only a single opening. An alimentary canal has two openings (a mouth and anus) between its digestive tubes unlike the gastrovascular cavity in which food is ingested and eliminated through the same opening.
Here is your Answer.
Answer is A. Archaebacteria
Archaebacteria are a type of single-cell organism. They are a group of most primitive prokaryotes which are believed to have evolved immediately after the evolution of the first life. Thermoacidophiles are the archaebacteria which can tolerate high temperature as well as high acidity. They often live in hot sulfur springs where the temperature may be as high as 80°C and pH as low as 2. Examples are Thermoplasma, Thermoproteus.
