Chapter 22- Cytology: The Design and Function of Cells

Question 1

What are the microscopic, individual units of structure and function of living things on earth?

Answer 1

Cells

Question 2

What is the study of cells known as?

Answer 2

Cytology or cell biology

Question 3

The idea that God divided living things into smaller parts called cells began in 1665, when _________________ observed thin sections of cork with simple microscope of his own making and wrote a description of his observations.

Answer 3

Robert Hooke

Question 4

What is the theory that states that all living things are composed of living units called cells and of cell products and that all cells come from preexisting cells, and is universally accepted today as the most fundamental law in biology?

Answer 4

Cell theory

Question 5

The size of an organism is determined by the _________________, not the size of its cells.

Answer 5

Number of its cells

Question 6

Before the mid-20th century, living cells were regarded as simple bags of an amorphous gel or slime called ______________, thought to be a slush of amino acids, protein, fat, and carbohydrates.

Answer 6

“Protoplasm”

Question 7

What are the three main parts in every cell?

Answer 7

Nucleus
Cytoplasm
Membrane

Question 8

One of the largest and most important cell parts is the _______________, the “control center” of the cell, and controls the life of the cell and determines the physical characteristics of the organism.

Answer 8

Nucleus

Question 9

The master program is encoded in molecules of __________, which governs the construction and operation of the cell and contains the “blueprints” used to construct the cell’s machinery.

Answer 9

DNA

Question 10

The nucleus is separated from the rest of the cell by the:

Answer 10

Nuclear envelope

Question 11

Large protein complexes in the envelope called ____________ serve as “gates,” regulating the transport of large molecules into and out of the nucleus.

Answer 11

Nuclear pores

Question 12

In human cells, the DNA is divided into how many molecules?

Answer 12

46

Question 13

Embedded within the nucleus is a distinct region called the ______________, where ribosomes are assembled.

Answer 13

Nucleolus

Question 14

Embedded within the nucleus is a distinct region called the nucleolus, where ____________, the protein factories of the cell, are assembled.

Answer 14

Ribosomes

Question 15

Within the cell membrane is a jellylike fluid known as the _________________, which contains an extraordinary diversity of organelles, or “little organs,” as well as numerous dissolved chemicals.

Answer 15

Cytoplasm

Question 16

Large protein molecules called ______________ are found both in cytoplasm and in the organelles, carrying out various chemical reactions to produce energy, transform raw materials into useful substances, or break down old proteins to be recycled.

Answer 16

Enzymes

Question 17

To prevent a cell from being squashed or distorted by the slightest external pressures, God designed the cell with an intricate internal skeleton, called the ________________, to help maintain its shape, and is composed primarily of microtubules.

Answer 17

Cytoskeleton

Question 18

The cytoskeleton of a cell is composed primarily of ________________, which are hollow, rodlike filaments composed of a protein called tubulin.

Answer 18

Microtubules

Question 19

In human and animal cells, the microtubule-organizing center is a structure called the ________________, which is located near the nucleus, at the center of the cell.

Answer 19

Centrosome

Question 20

The centrosome contains the ___________________, a pair of cylindrical structures made of tubulin and play an important role in cell movement and division.

Answer 20

Centrioles

Question 21

The “power plants” of a cell are organelles known as ___________________, which oxidizes or “burns” carbohydrates and fats and uses the energy to produce ATP.

Answer 21

Mitochondria

Question 22

What is one of the major differences between plant and animal cells which are very complex organelles and in which the complex reactions of photosynthesis occur?

Answer 22

Chloroplasts

Question 23

In a living cell, proteins are manufactured by special “protein factories” called ______________ which assemble amino acids into complex proteins, guided by “blueprints” from the cell’s nucleus.

Answer 23

Ribosomes

Question 24

The cytoplasm is filled with a dense network of membranes called _________________, which is a network of interconnected sacs and tubules that is connected to the nuclear envelope and extends throughout the cell.

Answer 24

Endoplasmic reticulum (ER)

Question 25

When a ribosome is making a protein to be secreted outside the cell or destined for one of the cell’s many membranes, it attaches itself to the endoplasmic reticulum (ER) and injects the protein directly into the ER internal cavity, or:

Answer 25

Lumen

Question 26

Because the ribosomes give the endoplasmic reticulum (ER) a rough appearance, the ER near the nucleus is called:

Answer 26

Rough ER

Question 27

Because the endoplasmic reticulum(ER) farther from the nucleus has a smoother appearance than that near the nucleus, it is called:

Answer 27

Smooth ER

Question 28

Proteins that are manufactured in the rough ER are transported to one of the ________________, structures that serve as the “shipping centers” of the cell. And the purpose of this is to receive proteins manufactured in the rough ER, modify them if needed, package them in vesicles, and ship then to their final destinations.

Answer 28

Golgi complexes

Question 29

What is an organelle found in the cell that is a special type of vesicle that functions as a recycling center, and can be used to destroy bacteria that invade body cells, and also serve an important function in the embryonic development of fingers and toes?

Answer 29

Lysosomes

Question 30

One of the most obvious characteristics of the cytoplasm in plant cells is the presence of a large _____________ or storage space, which recycle proteins and other large molecules, serve as storage compartments, and allow the cell to regulate its size and water pressure by swelling or shrinking it.

Answer 30

Vacuole

Question 31

The contents of human and animal cells are separated from the outside environment by a very thin, flexible barrier called the ______________. Within the borders of it operate the most complicated processes in creation, and failure of it brings instant death.

Answer 31

Cell membrane

Question 32

A cell’s membrane is composed of special lipid molecules called _________________, with a small amount of cholesterol added to maintain the desired flexibility. And these molecules cluster back to back, forming a two-layered structure referred to as a lipid bilayer.

Answer 32

Phospholipids

Question 33

Outside the cell membrane, plant cells manufacture a rigid, boxlike structure called the _________________. This layer serves to stiffen the cell, allowing the plant to stay upright even though it lacks a skeleton.

Answer 33

Cell wall

Question 34

A living cell must remain fantastically bust just to keep functioning and to maintain a stable internal environment, a condition known as:

Answer 34

Homeostasis

Question 35

A cell must maintain a certain internal _____________, or relative concentration of acids and bases. Deviating from the proper amount of this will alter the delicate molecules in the cell.

Answer 35

pH

Question 36

What is the breakdown of chemical substances, such as glucose, within living cells for the purpose of releasing energy, and is used to synthesize ATP?

Answer 36

Cellular respiration

Question 37

Cellular respiration is used to synthesize the special phosphorus compound called _____________, which serves as the energy carrier of the cell and as a convenient form for the temporary storage of chemical energy.

Answer 37

ATP

Question 38

What is the movement of molecules across the cell membrane from a place of lower concentration to a place of higher concentration with the expenditure of energy?

Answer 38

Active transport

Question 39

What is the process of taking in large substances known as?

Answer 39

Endocytosis

Question 40

What are the two basic methods that the cell uses to to accomplish the task of endocytosis?

Answer 40

Phagocytosis

Pinocytosis

Question 41

What is one of the methods that the cell uses to accomplish the task of endocytosis which means “cell eating,” and is the process used by certain cells to surround solid particles with the cell membrane and then engulf them?

Answer 41

Phagocytosis

Question 42

What is one of the methods that the cell uses to accomplish the task of endocytosis which means “cell drinking,” and is this method by which the cell membrane allows an amount of liquid to enter the cell before it pinches off to entrap the engulfed material?

Answer 42

Pinocytosis

Question 43

Cellular waste products are eliminated from the cytoplasm by the process of _______________. In this process, secretion-containing vesicles move to the surface of the cell and open, spilling their contents to the exterior.

Answer 43

Exocytosis

Question 44

What is a large, moveable whiplike tail that extends from the cell, euglenas, dinoflagellates, and sperm cells are examples of cells that move by means of this?

Answer 44

Flagellum

Question 45

Cells such as paramecia move by means of ____________, tiny hairlike projections that extend from the cell membrane.

Answer 45

Cilia

Question 46

During the lifetime of many organisms, the process of one cell doubled to make two and then those two doubled to make four and so forth has occurred billions or trillions of times. Biologists study this reproductive process and summarize it as part of a:

Answer 46

Cell cycle

Question 47

Cytologists divide the cell cycle into four phases: G1, S, G2, and M. The first three phases, G1, S, and G2 are sometimes referred to collectively as _______________, which is the majority of the cell’s life and is the stage between cell divisions.

Answer 47

Interphase

Question 48

During the S phase of the cell cycle, what is carefully replicated so that there are two copies of it before the cell divides?

Answer 48

DNA

Question 49

What is the genetic material within the nucleus, consisting of DNA molecules and their protein “spools” that becomes organized into threadlike structures called chromosomes when the cell begins to divide?

Answer 49

Chromatin

Question 50

If we observe the cell as it begins to divide, we note that the chromatin becomes organized into threadlike structures called:

Answer 50

Chromosomes

Question 51

The process of mitosis consists of what four steps?

Answer 51

Prophase
Metaphase
Anaphase
Telophase

Question 52

What is the first of the four steps of mitosis, where the cell packages its DNA, which was spread throughout the entire nucleus during interphase, into chromosomes that are visible through a microscope?

Answer 52

Prophase

Question 53

In the space between paired centrioles, arcs of microtubules become visible. These fibers and the centrioles that produce them form the _________________, the structure to which chromosomes become attached during metaphase.

Answer 53

Spindle apparatus

Question 54

During what process in human and animal cells does the cell membrane pinch in half, forming two daughter cells; but in plant cells it takes place not by pinching, but by the formation of a cell plate which then forms a new cell wall between the two daughter cells?

Answer 54

Cytokinesis

Question 55

What process takes place during the M phase of the cell cycle, which is also known as cell division, and is the process where the nucleus of a cell divides to generate two nuclei with the same number of chromosomes as the original nucleus?

Answer 55

Mitosis