HIV attacks which type of immune cells? MCQ with Answer and Explanation

Explanation:
Rabi crops are sown in winter (October-December) and harvested in spring (March-April). Wheat, gram, mustard, pea are common rabi crops. Rice, maize, and sugarcane are kharif crops, sown with the onset of monsoon and harvested in autumn. This distinction is based on seasonal cultivation patterns in Indian agriculture. Rabi crops require cool growing season and warm harvest season.

Explanation:
Epistasis is a form of gene interaction where the expression of one gene (the epistatic gene) masks, suppresses, or modifies the expression of another non-allelic gene (the hypostatic gene). This alters the expected Mendelian dihybrid ratio (9:3:3:1) into modified ratios like 9:7 (complementary), 9:3:4 (recessive epistasis), or 12:3:1 (dominant epistasis). Pleiotropy is one gene affecting multiple traits, and linkage is genes being on the same chromosome.

Explanation:
The Islets of Langerhans are the endocrine (hormone-producing) portions of the pancreas. They are clusters of cells scattered throughout the pancreatic tissue, comprising about 1-2% of the pancreas's mass. They contain several cell types, primarily alpha cells (secreting glucagon), beta cells (secreting insulin), delta cells (secreting somatostatin), and F cells (secreting pancreatic polypeptide). These hormones are crucial for regulating blood glucose levels.