The technique used to measure the concentration of a solution based on light absorption is: MCQ with Answer and Explanation

Explanation:
Edward Jenner developed the first successful vaccine using cowpox to protect against smallpox in 1796. Pasteur developed rabies vaccine, Salk polio, Koch identified TB bacterium.

Explanation:
Kingdom Monera includes all prokaryotic organisms, which lack a true nucleus and membrane-bound organelles. Cyanobacteria (blue-green algae) are prokaryotes and thus belong to Monera. Amoeba is a protist, while yeast and mushrooms are fungi, which belong to the Kingdom Fungi and are eukaryotic.

Explanation:
Leptin is a hormone secreted by adipose tissue that signals the status of body fat stores to the brain. It acts primarily on the arcuate nucleus (ARC) of the hypothalamus. The ARC contains two key populations of neurons: one that co-expresses Neuropeptide Y (NPY) and Agouti-related peptide (AgRP), which stimulate appetite, and another that expresses Pro-opiomelanocortin (POMC) and Cocaine- and amphetamine-regulated transcript (CART), which suppress appetite. Leptin binds to receptors on these neurons, inhibiting the NPY/AgRP neurons and stimulating the POMC/CART neurons, thereby reducing appetite and increasing energy expenditure.