Plant Science Resource

  1. Cell wall consists of (A) One main layer (B) Two main layers (C) Three main layers (D) Four main layers 2. Lysosomes have (A) Single-layered membrane (B) Double-layered membrane (C) Three-layered membrane (D) No membrane 3. Leucoplast are found (A) Petals (B) Ripened fruits (C) Underground parts (D) Leaves 4. Which of the following are regularly assembled and disassembled during cell cycle. (A) Microtubules (B) Intermediate filaments (C) Both A and B (D) None of these   5. SER is abundant in cells that are involved in (A) Lipid metabolism (B) Protein metabolism (C) Glucose metabolism (D) Calcium metabolism   6. Most dense part of the cell (a) vacuole (b) grana (c) nucleolus (d)Perinuclear space   7. A semi permeable membrane is stretched across a chamber filled with water. The membrane is only permeable to water. 60 mg of salt is added to the left side of the chamber. Which of the following...

 Practice set 1 with solution 03.11.2020 (Part 2) 21) Sephadex has an exclusion limit of 80, 000 molecular weight for globular proteins. When this material was used to separate alcohol dehydrogenase (MW 150, 000) from b amylase (MW 200, 000) the result will be? (a) Alcohol dehydrogenase elutes first     (b) β-amylase elutes first (c) β-amylase will not elute                      (d) No separation.   Ans:(d) No separation occurs because in size exclusion chromatography small molecules can enter the poresin the beads where as larger molecules can not. So, larger molecules move faster and elute first. But in this case, exclusion limit of sephadex is 80,000 molecular weight and molecular weight of both alcohol dehydro-genase and α-amylase is higher than the exclusion limit. Thus, both are elute simultaneously without entering in the beads.   22) I...