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

Explanation:
Penicillin and other beta-lactam antibiotics (cephalosporins, carbapenems) inhibit the transpeptidase enzyme involved in cross-linking peptidoglycan, weakening the cell wall and causing bacterial lysis. Tetracycline and streptomycin inhibit protein synthesis by acting on ribosomes. Chloramphenicol also inhibits protein synthesis. Penicillin is most effective against actively dividing gram-positive bacteria.

Explanation:
In C4 plants like maize and sugarcane, CO₂ is initially fixed in mesophyll cells by PEP carboxylase, producing a four-carbon compound oxaloacetic acid (OAA), which is then converted to malate or aspartate and transported to bundle sheath cells. Here, CO₂ is released and enters the Calvin cycle. This adaptation minimizes photorespiration.

Explanation:
Binary fission is a type of asexual reproduction in prokaryotes where the cell divides into two identical daughter cells after DNA replication. Mitosis and meiosis are eukaryotic. Budding occurs in yeast and some bacteria.