Day 2_Semester 1_TEKS 4B_DOL

Which of the following best explains the process illustrated in the above diagram?

• Passage of water molecules through a semi-permeable membrane to equalize concentration

• Transport of molecules across a membrane from a high to low concentration gradient by means of a carrier molecule

• Movement of molecules against a concentration gradient expending energy

• Separation of suspended particles from a fluid environment to a non-fluid environment through a porous membrane

A scientist is investigating cell transport. She observes molecules being transported into a cell through proteins present in the cell membrane. These proteins do not use energy to transport the molecules. Which of the following best explains the type of cell transport observed by the scientist?A scientist is investigating cell transport. She observes molecules being transported into a cell through proteins present in the cell membrane. These proteins do not use energy to transport the molecules. Which of the following best explains the type of cell transport observed by the scientist?

• Active transport because membrane proteins were used

• 
  Diffusion because the molecules were entering the cell

• Facilitated diffusion because the proteins were not using energy

• Osmosis because the molecules were moving against the concentration gradient

How does the cell membrane help to maintain the health of the cell?

• 
  By providing support and structure for the cell

• By regulating the transport of materials in and out of the cell

• 
  By manufacturing protein to provide energy for the cell

• 
  By storing food as future energy for the cell

A few drops of Lugol’s iodine solution placed in a beaker of water will turn the water red. A starch solution was poured into a length of dialysis tubing, and the ends were tied. The starch solution was clear and colorless. The tubing was then dropped into a beaker of iodine solution. After 10 minutes, the clear and colorless starch solution turned black, and the iodine water remained red.

Refer to the reading passage and diagram above. If the dialysis tubing represents a cell membrane, which of the following statements describes what is being observed in the changing color of the starch solution?

• 
  Iodine cannot pass through a membrane.

• A semipermeable membrane will allow diffusion of selected molecules.

• Starch can be easily diffused through a membrane.

• A permeable membrane diffuses chemicals in and out of its surface.

To maintain homeostasis, cells absorb and excrete substances through the phospholipid bilayer of the cell membrane. In which process do cells use vesicles to excrete substances?

• Facilitated diffusion

• Exocytosis

• 
  Endocytosis

• Simple diffusion

Which statement is incorrect?

• Some molecules diffuse through carrier proteins

• Molecule transport across a membrane can occur through endocytosis or exocytosis

• 
  Osmosis is a type of passive transport and requires no energy input from the cell

• An isotonic solution has a higher concentration of dissolved particles than the cell

Some students used vinegar to dissolve away the shells of three eggs and used these eggs as models of human red blood cells. The students observed the changes in the eggs when they were placed in different solutions. Which statement best describes the role of the cell membrane in this model?

• The cell membrane is an impermeable barrier that prevents water from entering the cell.

• The cell membrane allows water to enter and leave the cell

• The cell membrane allows solutes to enter the cell, which causes the cell to shrink

• The cell membrane removes solutes from the environment

The cell membrane only lets certain things in and out, for that reason, it is said to be

• Permeable

• Semi-permeable

• Impermeable

Which type of movement across a cell’s plasma membrane requires energy supplied by ATP?

• Passive transport

• Simple diffusion

• Active transport

• Osmosis

A type of cellular transport is shown.

Which type of membrane transport is depicted in the diagram? AND how do you know?