According to the original horizontality law, the sediments initially were all deposited in a horizontal manner, and were spread extensively in all the direction, until they find any feature that cross-cuts them
Many different species of blue-green algae occur in lakes
Answer:
This implies that DNA and proteins evolved after RNA.
Explanation:
It is believed that RNA predated today's cells in evolutionary history. RNA existed as the genetic material of the primitive cells of the time that were mainly constituted of globules of fat oil suspended in water in the oceans and lakes. Even in cells today, RNA molecules themselves can act as catalysts such as in the case of peptidyl transferase reaction that takes place on the ribosome.
Answer:
Cnidaria
→ Organisms have specialized stinging cells
→ Two type of body plans exist - polyp and medusa
Porifera
→ Organisms lack symmetry
→ Adult forms are sessile
→ Organisms obtain food by filtering water
→ Phenomenon of alternation of generation is observed.
Explanation:
Cnidaria, also known as the coelenterata, is a phylum of mostly marine animals having about 9,000 living species. Some of them include the corals, hydras, jellyfish, sea anemones, sea whips, etc. They possess specialized cells known as cnidocytes ( also known as “stinging cells”). These cells can seen around the mouth and tentacles cnidarian. They immobilize their prey with toxins. These Cnidaria have two body plans and which are polyp and medusa.
The phylum Porifera are known as the pore bearers. It has about 5000 species. Their adult forms are sessile. They live permanently attached to rocks. They can under alternation of generation. They possess no organs in their bodies. Also, they lack symmetry. They can be referred t as filter feeders because they obtain food by filtering water.