The number of chromosomes in a human zygote is: MCQ with Answer and Explanation

Explanation:
Binary fission is the primary and most common method of asexual reproduction in bacteria. In this process, the bacterial cell replicates its DNA and then divides into two identical daughter cells. Under optimal conditions, some bacteria can divide every 20 minutes. Bacteria can also exchange genetic material through processes like conjugation, transformation, and transduction.

Explanation:
The juxtaglomerular apparatus (JGA) is a specialized structure where the distal convoluted tubule (DCT) comes into contact with the afferent arteriole. It consists of juxtaglomerular cells (modified smooth muscle cells in the afferent arteriole that secrete renin), macula densa cells (modified DCT cells that sense NaCl concentration), and extraglomerular mesangial cells. It plays a crucial role in regulating blood pressure and glomerular filtration rate via the renin-angiotensin-aldosterone system.

Explanation:
Photosynthesis converts CO₂ and water into glucose using light energy, fixing carbon. Respiration releases CO₂, combustion burns organic matter, decomposition breaks down dead matter. Photosynthesis is the main route of carbon entry into the biosphere.