Which statement is consistent with the cell theory presented in the notes? A. All cells possess a cell wall. B. Cells arise spontaneously from non-living matter. C. All living organisms are composed of one or more cells. D. Only multicellular organisms.

1. The cell theory states that all living organisms are composed of one or more cells, cells are the basic unit of life, and all cells arise from pre-existing cells.

• C) All living organisms are composed of one or more cells.

2. The observation that a single cell can perform all essential life functions (nutrition, respiration, excretion, and reproduction) directly supports the idea that the cell is the fundamental unit of life.

• B) The cell is the basic unit of structure and function in living organisms.

3. Prokaryotic cells lack a membrane-bound nucleus and other membrane-bound organelles, which are characteristic features of eukaryotic cells.

• C) Absence of a membrane-bound nucleus.

4. Ribosomes are responsible for protein synthesis and are found in both prokaryotic (70S) and eukaryotic (80S) cells.

• C) Ribosome.

5. The presence of a cell wall, chloroplasts (for photosynthesis), and a large central vacuole are all characteristic features of a plant cell.

• B) plant.

6. The nucleus contains the cell's genetic material (DNA) and controls all cellular activities by regulating gene expression.

• A) nucleus.

7. Mitochondria are the primary sites of cellular respiration, where ATP (energy) is produced. Cells with high energy demands would have many mitochondria.

• B) mitochondria.

8. The inner mitochondrial membrane is folded into cristae, which significantly increases the surface area available for the enzymes and electron transport chain components involved in ATP production.

• B) provide a large surface area for reactions associated with ATP production.

9. Ribosomes are the cellular organelles responsible for synthesizing proteins through the process of translation.

• A) Ribosome.

10. Proteins destined for export are synthesized on the rough endoplasmic reticulum (RER) and then processed, modified, and packaged by the Golgi apparatus before secretion.

• A) rough endoplasmic reticulum and Golgi apparatus.

11. The Golgi apparatus (also called Golgi complex or Golgi body) is responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles.

• B) Golgi apparatus.

12. Lysosomes contain hydrolytic enzymes that break down waste materials, cellular debris, and worn-out organelles through intracellular digestion.

• A) lysosomes.

13. The rigid cell wall in plant cells provides structural support and prevents the cell from bursting due to high internal osmotic pressure (turgor pressure).

• B) Cell wall.

14. The fluid mosaic model describes the cell membrane as a phospholipid bilayer with various proteins embedded within it or associated with its surfaces.

• B) a phospholipid bilayer with associated proteins.

15. A selectively permeable membrane allows certain substances to pass through while restricting others, thereby regulating what enters and leaves the cell.

• C) regulates which substances enter and leave the cell.

16. Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration, down a concentration gradient, without the input of metabolic energy.

• B) Net movement of particles from higher to lower concentration.

17. An increase in the concentration gradient means there is a larger difference in concentration between two areas, which leads to a faster rate of diffusion.

• C) Increasing the concentration gradient.

18. Oxygen moves from the alveoli, where its partial pressure is high, to the blood, where its partial pressure is lower, by passive diffusion across the respiratory membrane.

• C) diffusion.