कोशिका में तारककेंद्र (सेंट्रीओल) का मुख्य कार्य क्या है?

Arrange the following events in the correct chronological order during receptor-mediated endocytosis of LDL and its subsequent intracellular fate: A. LDL binds to the LDL receptor in a clathrin-coated pit at the plasma membrane B. Dynamin oligomerises at the neck of the coated pit and hydrolyses GTP to pinch off the vesicle C. Clathrin triskelions are recruited via AP-2 adaptor binding to the NPXY internalisation signal of the LDL receptor D. Acidification of the early endosome (pH ~6) causes dissociation of LDL from its receptor E. LDL receptor is recycled to the plasma membrane via Rab11-positive recycling endosomes F. Cholesterol esters are hydrolysed by lysosomal acid lipase after late endosome–lysosome fusion

A researcher treats cultured mammalian cells with Brefeldin A (BFA) for 30 minutes and then labels newly synthesised proteins with 35S-methionine. She finds that: - Labelled proteins accumulate in the ER. - The cis-Golgi marker GM130 redistributes to the ER. - Lysosomal enzyme precursors (bearing mannose-6-phosphate) are secreted into the medium instead of reaching lysosomes. Which of the following mechanistic statements best explains all three observations?

Consider the following statements regarding the selectivity filter of voltage-gated K+ channels: I. The signature sequence TVGYG forms the selectivity filter using backbone carbonyl oxygens to mimic water molecules of K+ hydration shell. II. Na+ passes through K+ channels at about 1/1000th the rate of K+ because Na+ is too large to fit the selectivity filter geometry. III. The selectivity filter has four K+-binding sites (S1–S4), and two K+ ions simultaneously occupy alternate sites (S1,S3 or S2,S4) due to electrostatic repulsion. IV. Tetraethylammonium (TEA) blocks K+ channels by occluding the selectivity filter from the extracellular side. Which of the above statements are correct?

Which of the following statements is/are correct? I. Prokaryotic cells contain a single chromosome. II. Eukaryotic cells contain more than one chromosome.

Which of the following scientists coined the term 'cell'?

Which scientist demonstrated that the nucleus determines the characters of the cell and ultimately the organism through experiments on Acetabularia?

What is the total number of daughter cells produced from a single parent cell after a complete meiotic division?

A signal peptide usually consists of how many amino acids?