In a typical angiosperm embryo sac, the number of haploid nuclei is: MCQ with Answer and Explanation

Explanation:
During telophase, the chromatids reach the poles, decondense, and the nuclear envelope reassembles around each set, forming two daughter nuclei. The spindle disappears. Prophase involves nuclear envelope breakdown, metaphase aligns chromosomes, and anaphase separates chromatids. Cytokinesis often overlaps with telophase, dividing the cytoplasm.

Explanation:
Platelets (thrombocytes) are small, anucleate cell fragments that adhere to the site of injury, release clotting factors, and aggregate to form a platelet plug, initiating the coagulation cascade. RBCs transport oxygen, WBCs defend against infection, and plasma proteins like albumin maintain osmotic balance. Clotting factors are also present in plasma, but platelets are the primary cellular component.

Explanation:
Azotobacter is a free-living, aerobic, nitrogen-fixing soil bacterium used as a biofertilizer for non-legume crops like wheat, maize, and cotton. Rhizobium is symbiotic, Nostoc is a cyanobacterium (algal biofertilizer), and mycorrhiza is a fungal symbiont that enhances phosphorus uptake. Biofertilizers reduce the need for chemical nitrogen fertilizers and are eco-friendly.