Which hormone regulates the blood calcium level by lowering it? MCQ with Answer and Explanation

Explanation:
Panthera leo is the binomial name for the lion. Panthera tigris is the tiger, Felis catus is the domestic cat, and Canis lupus is the grey wolf. The genus Panthera includes roaring cats: lion, tiger, jaguar, and leopard. Binomial nomenclature uses a capitalized genus and lowercase species epithet, both italicized.

Explanation:
Restriction enzymes (restriction endonucleases) are molecular 'scissors' that cut DNA at specific, highly specific recognition sequences (palindromic sequences). They are essential tools in genetic engineering for cutting both the source DNA (gene of interest) and the vector DNA at specific sites, creating compatible ends for ligation. DNA ligase is used to join the fragments.

Explanation:
Sea cucumber (class Holothuroidea) belongs to phylum Echinodermata, characterized by radial symmetry, a water vascular system, and a calcareous endoskeleton. Sea anemone is a cnidarian, sea horse a bony fish, sea urchin is also an echinoderm. Note: sea urchin is also an echinoderm, so both B and D are echinoderms. I need a unique correct answer. I'll modify: Sea cucumber is correct; sea urchin is also echinoderm, so I'll replace sea urchin with a non-echinoderm.