Question

1. which of the following types of transport requires energy? (a) simple or passive diffusion; (b) facilitated diffusion; (c) active transport. 30. which of the following types of transport requires no transport protein, but rather, only a concentration gradient of a particular solute? (a) simple or passive diffusion; (b) facilitated diffusion; (c) active transport. 31. which of the following types of transport are required to move solutes against their concentration gradient? (a) simple or passive diffusion; (b) facilitated diffusion; (c) active transport; (d) none of the above. 32. a “heart - healthy diet” is rich in unsaturated fatty acids. this statement refers to having in your diet: (a) plenty of cholesterol; (b) no cholesterol at all; (c) plenty of cis fatty acids; (d) plenty of trans fatty acids. 33. what are the criteria for a solute to be able to diffuse through a cell membrane, without a transport protein? (a) small; (b) hydrophobic; (c) no net charge; (d) all of the above. 34. which of the following types of molecules are amphipathic? (a) nucleic acids; (b) proteins; (c) phospholipids; (d) amino acids. 35. which of the following distinguish between prokaryotic and eukaryotic cells? (a) cell membrane; (b) dna; (c) nucleus; (d) ribosomes. 36. in the process of osmosis, a. solute particles run down their concentration gradient (from an area of high to an area of low concentration). b. solute particles run up their concentration gradient (from an area of low to an area of high concentration). c. water runs down its concentration gradient (from an area of high to an area of low concentration). d. water runs up its concentration gradient (from an area of low to an area of high concentration). 37. which statement accurately describes biological membranes? a. a bilayer of lipids, whose hydrophilic heads point to the interior of the bilayer and are shielded from the extracellular and cytoplasm. b. a bilayer of lipids, whose hydrophilic heads point to the exterior of the bilayer and whose hydrophobic tails are shielded from the exterior and cytoplasm. c. a bilayer of lipids, whose hydrophobic heads point to the exterior of the bilayer and whose hydrophilic tails are shielded from the exterior and cytoplasm. d. a bilayer of lipids, whose hydrophillic tails point to the exterior of the bilayer and whose hydrophobic heads are shielded from the exterior and cytoplasm. 38. which of the following features distinguishes plant cells from animal cells? (a) mitochondria; (b) being green; (c) chloroplasts; (d) nucleus.

Explanation:

1. Active transport moves substances against their concentration gradient and requires energy. Simple and facilitated diffusion are passive and do not require energy.
2. Simple or passive diffusion only needs a concentration gradient and no transport protein. Facilitated diffusion needs transport proteins and active transport also uses proteins.
3. Active transport is the process that moves solutes against their concentration gradient. Simple and facilitated diffusion move solutes along the gradient.
4. Unsaturated fatty - acids in a heart - healthy diet often refer to cis fatty acids. Cholesterol is not directly related to unsaturated fatty acids in this context.
5. Small, hydrophobic, and uncharged solutes can diffuse through a cell membrane without a transport protein.
6. Phospholipids have a hydrophilic head and a hydrophobic tail, making them amphipathic. Nucleic acids, proteins, and amino acids do not have this characteristic in the same membrane - related context.
7. The presence of a nucleus distinguishes eukaryotic cells from prokaryotic cells. Both have cell membranes, DNA, and ribosomes.
8. In osmosis, water moves down its concentration gradient (from an area of high water concentration to an area of low water concentration).
9. Biological membranes are a bilayer of lipids with hydrophilic heads pointing to the exterior of the bilayer and hydrophobic tails shielded from the exterior and cytoplasm.
10. Chloroplasts are present in plant cells but not in animal cells. Mitochondria and nuclei are present in both, and not all plant cells are green.

Answer:

1. C. active transport
2. A. simple or passive diffusion
3. C. active transport
4. C. plenty of cis fatty acids
5. D. all of the above
6. C. phospholipids
7. C. nucleus
8. C. Water runs down its concentration gradient (from an area of high to an area of low concentration)
9. B. A bilayer of lipids, whose hydrophilic heads point to the exterior of the bilayer and whose hydrophobic tails are shielded from the exterior and cytoplasm
10. C. chloroplasts