Question

1. at cell contain cell membranes. which of the following describes the function of cell membranes?

a. cell membranes are composed of carbohydrate chains, which allow all materials to enter and leave the cell
b. cell membranes are composed of cellulose, which provides rigidity for the cell
c. cell membranes are composed of phospholipids, which allows flexibility to be provided by the cell
d. cell membranes are composed of lipid molecules, which provide a binding structure

1. which organelles allow plants to support heavy structures such as leaves and flowers?

a. the cell membranes because they regulate what enters and leaves the cells
b. the chloroplasts because they convert sunlight into chemical energy
c. the golgi apparatus because it packages proteins for storage in the cells
d. the vacuoles because they are filled with fluid, which provide rigidity

1. in eukaryotic cells, a number of organelles allow the cell to produce and distribute proteins. where are proteins modified, sorted, and packaged?

a. golgi apparatus
b. ribosomes
c. rough endoplasmic reticulum
d. smooth endoplasmic reticulum

Explanation:

Question 8 (assuming the second question numbered 8, about plant organelles for support):

Step1: Analyze each option

• Option a: Cell membranes regulate entry/exit, not support. Eliminate.
• Option b: Chloroplasts convert light to energy (photosynthesis), not support. Eliminate.
• Option c: Golgi apparatus packages proteins, not support. Eliminate.
• Option d: Vacuoles in plant cells are large, filled with fluid (cell sap), providing turgor pressure for structural support. This matches the need to support heavy structures.

Step1: Recall organelle functions

• Ribosomes: Synthesize proteins (not modify/sort/package). Eliminate b.
• Rough ER: Synthesizes and initializes protein modification, but main modification/sorting/packaging is Golgi. Eliminate c.
• Smooth ER: Lipid synthesis, detoxification (not protein processing). Eliminate d.
• Golgi apparatus: Receives proteins from ER, modifies, sorts, and packages them for transport (secretion or storage). This matches the question.

Answer:

d. the vacuoles because they are filled with fluid, which provide rigidity

Question 10 (protein modification, sorting, packaging):