Step 1: Understanding Cnidocytes.
Cnidocytes are specialized cells found only in the phylum Cnidaria, which includes organisms like jellyfish, corals, and sea anemones. These cells contain a stinger (nematocyst) used for defense and capturing prey.
Step 2: Explanation of the other options.
Erythrocytes (red blood cells) are found in all vertebrates.
Myocytes (muscle cells) are found across many phyla, not limited to a single one.
Neurocytes (nerve cells) are also widespread across multiple animal phyla.
A patch of forest (I) has been declared as a protected area. Conservationists have surveyed three other patches of forest (II, III and IV) and can only recommend one of them for protection. In the figure below, each letter denotes a different species of frog. The conservationists recommend that Patch IV should be protected. Which one of the following metrics is this decision based on?
