The restriction enzyme EcoRI recognizes the palindromic DNA sequence 5'-GAATTC-3' and cuts the DNA between the: MCQ with Answer and Explanation

Explanation:
Bacteria exhibit diverse roles; many are beneficial (e.g., gut flora, nitrogen fixers, decomposers), while some are pathogenic and cause diseases. Fungi are extensively used in food production, such as yeast (Saccharomyces) in baking and brewing, and molds (Penicillium) in cheese making (e.g., Roquefort, Camembert). Viruses are considered non-living outside a host cell because they lack metabolic machinery and cannot replicate independently; they only exhibit living characteristics when inside a host. Thus, statements 1 and 2 are correct.

Explanation:
Immunoglobulin A (IgA) is the primary antibody found in mucosal secretions, including saliva, tears, nasal secretions, breast milk (colostrum), and the respiratory and gastrointestinal tracts. It plays a crucial role in mucosal immunity by preventing the attachment of pathogens to epithelial cells, a process known as immune exclusion. IgG is the most abundant in blood, IgM is the first to be produced in an infection, and IgE is involved in allergies.

Explanation:
Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopamine-producing neurons in the substantia nigra region of the brain. This leads to motor symptoms like tremors, rigidity, and bradykinesia. L-DOPA (levodopa), a precursor of dopamine, is used in treatment. Acetylcholine is related to Alzheimer's, serotonin to depression.