Consider the following statements about DNA fingerprinting: 1. It uses VNTRs (variable number tandem repeats). 2. It can be used in paternity testing. 3. It requires amplification by PCR. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
Immunoglobulin G (IgG) is the most abundant antibody in blood plasma, providing long-term immunity and crossing the placenta. Immunoglobulin E (IgE) is present in small amounts and binds to mast cells, triggering the release of histamine during allergic reactions. Immunoglobulin A (IgA) is predominantly found in mucosal secretions like saliva, tears, and breast milk, providing localized mucosal immunity. All statements are correct.

Explanation:
In a closed circulatory system (e.g., humans, annelids, cephalopods), blood is always enclosed within vessels (arteries, veins, capillaries) and is distinct from interstitial fluid. Open systems (arthropods, most mollusks) have hemolymph bathing organs in sinuses. The lymphatic system returns fluid to blood. A portal system connects two capillary beds.

Explanation:
The vacuole’s solute concentration draws water, generating turgor pressure that maintains cell rigidity. This is essential for support in plants. R explains A.