Chapter 3: Cells

Question 1

Nerve Cells: special features

Answer 1

Long extensions allow these cells to quickly transmit electrical impulses from one part of the body to another.

Question 2

Muscle Cells: special features

Answer 2

Elongated, thread-like fibers can shorten to allow body parts to move.

Question 3

Red Blood Cells: special features

Answer 3

Concave shape allows these cells to bend and squeeze through tiny blood vessels.

Question 4

Gland Cells: special features

Answer 4

Intracellular sacs store and release substances, such as hormones, enzymes, mucus, and sweat.

Question 5

Immune Cells: special features

Answer 5

These cells can recognize and destroy foreign invaders(such as viruses, fungi, and bacteria) some engulf or destroy foreign cells directly; others manufacture antibodies.

Question 6

Plasma Membrane

Answer 6

The boundary of the cell

Question 7

Nucleus

Answer 7

The center of the cell

Question 8

Cytoplasm

Answer 8

A gel-like substance surrounding the nucleus and packed with various organelles and molecules each of which serves a specific function.

Question 9

Selective Permeability

Answer 9

meaning some substances, such as lipid-soluble molecules, pass through easily, while others do not.

Question 10

Nuclear Envelope

Answer 10

Double-layered membrane surrounding the nucleus

Question 11

Nuclear Pores

Answer 11

Perforating the nuclear envelope, these pores regulate the passage of molecules into the nucleus, as well as out of the nucleus.

Question 12

Chromatin

Answer 12

Thread-like structures composed of DNA and protein extending throughout the nucleoplasm

Question 13

Nucleolus

Answer 13

in the center of the nucleus

Question 14

Passive Transport

Answer 14

Mechanisms that don’t require the cell to expend energy (diffusion, osmosis, filtration, and facilitated diffusion)

Question 15

Diffusion

Answer 15

Involves the movement of particles from an area of higher concentration to lower concentration.

Question 16

Osmosis

Answer 16

involves the diffusion of water down the concentration gradient through a selectively permeable membrane.

Question 17

Filtration

Answer 17

occurs because of differences in pressure. water and dissolved particles are forced across a membrane from an area of higher to lower hydrostatic pressure.

Question 18

Facilitated diffusion

Answer 18

some molecules need other molecules to help, or facilitate, their movement across a membrane, higher to lower concentration gradient.

Question 19

Active Transport

Answer 19

solutes move up the concentration gradient-from areas of lesser to greater concentration. Requires energy which is provided in the form of ATP.

Question 20

Sodium-Potassium Pump

Answer 20

regulates the volume of fluid within cells, provides the electrical potential necessary for the nervous system activity, and helps heat production.

Question 21

Endocytosis

Answer 21

The form of vesicular transport that brings substances into the cell

Question 22

Exocytosis

Answer 22

uses vesicles to release substances outside of the cell.

Question 23

Phagocytosis

Answer 23

occurs when the cell engulfs a solid particle and brings it into the cell.

Question 24

Pinocytosis

Answer 24

Occurs when tiny vacuoles bring droplets of extracellular fluid containing dissolved substances into the cell. The cell then uses the engulfed fluid and nutrients.