Chapter 1

Question 1

Who was the first person to discover cells?

Answer 1

Robert Hooke

Question 2

In what year did Robert Hooke write about his findings on cells?

Answer 2

1665

Question 3

What did Robert Hooke observe through his microscope?

Answer 3

A slice of cork

Question 4

What term did Robert Hooke coin to describe the units he discovered?

Answer 4

Cells

Question 5

What does the term ‘cella’ mean in Latin?

Answer 5

A small room

Question 6

What is the cell theory?

Answer 6

All living things are composed of one or more cells

Question 7

What significant discovery in our time is compared to the cell theory?

Answer 7

The discovery of DNA

Question 8

What can a typical plant cell be likened to?

Answer 8

A large factory

Question 9

What are the raw materials that a plant cell uses?

Answer 9

Water, air, and soil

Question 10

What energy source does a plant cell use?

Answer 10

Sunlight

Question 11

How does a plant cell respond to increased productivity demands?

Answer 11

It builds an exact copy of its entire physical structure

Question 12

What is the approximate size of a typical plant cell?

Answer 12

1/2000 of an inch (0.05 mm)

Question 13

Fill in the blank: The cell theory states that all living things are composed of one or more _______.

Answer 13

Cells

Question 14

True or False: Robert Hooke’s discovery of cells was a minor advancement in scientific thought.

Answer 14

False

Question 15

What does the study of cells continue to reveal?

Answer 15

Surprises about what life is at microscopic and finer levels

Question 16

What is the composition of a cell membrane?

Answer 16

A cell membrane is composed of protein and fatty substances and controls the passage of water, foods, and selected minerals.

Question 17

What are organelles?

Answer 17

Organelles are small bodies suspended in the semi-liquid cytoplasm that specialize in the cell’s separate functions.

Question 18

What are chloroplasts and their function?

Answer 18

Chloroplasts are organelles unique to plants where photosynthesis takes place, using light energy to manufacture foods.

Chlorophyll, the green pigment essential for photosynthesis, is located within chloroplasts.

Question 19

What is the role of mitochondria?

Answer 19

Mitochondria extract energy from foods through the process of cellular respiration.

Question 20

What do ribosomes specialize in?

Answer 20

Ribosomes specialize in protein production.

Question 21

What is the function of the nucleus in a cell?

Answer 21

The nucleus is the control center of the cell, providing instructions for operation, maintenance, and reproduction.

Question 22

What are chromosomes and where are they located?

Answer 22

Chromosomes, bearing genes composed of DNA, are located in the nucleus and serve as blueprints for making more cellular factories.

Question 23

What is a vacuole?

Answer 23

A vacuole is a membrane-bound inner sac in plant cells that stores water, excess mineral nutrients, and toxic waste products from metabolism.

Question 24

What enhances the metabolism of cells?

Answer 24

The metabolism of cells is enhanced when groups of cells act in concert by exchanging foods and materials through interconnecting strands of cytoplasm called plasmodesmata.

Question 25

What surrounds the protoplasm of each cell?

Answer 25

The protoplasm of each cell is surrounded by a rigid cell wall that protects the living contents.

Question 26

What is the middle lamella?

Answer 26

The middle lamella is a thin layer of pectin that forms between adjacent cell walls, binding the cells together.

Question 27

What is the primary cell wall composed of?

Answer 27

The primary cell wall is largely composed of cellulose.

Question 28

What happens to the cell wall as a cell ages?

Answer 28

The cell wall may thicken by the addition of more cellulose and the introduction of lignin.

Question 29

What is lignin?

Answer 29

Lignin is a hardening substance that is introduced into the cell wall as it thickens.

Question 30

What constitutes the secondary wall of a cell?

Answer 30

The secondary wall is made up of additional cellulose layers and lignin.

Question 31

How do cell walls provide structural support to plants?

Answer 31

Cell walls give structural support, with rigidity proportional to the thickness of the walls.

Question 32

What indicates that a leaf is composed of thin-walled cells?

Answer 32

The lightweight, delicate structure of a leaf indicates it is composed of thin-walled cells.

Question 33

What happens to the living contents of a cell as the wall thickens?

Answer 33

As walls thicken, the space occupied by living contents decreases, diminishing the ability of water and oxygen to reach the cytoplasm.

Question 34

What percentage of a living tree's trunk and branches is composed of dead cells?

Answer 34

As much as 98 percent of a living tree's trunk and branches are composed of dead cells.

Question 35

What is the role of the remaining hollow cell walls in a plant?

Answer 35

The remaining hollow cell walls continue their supportive roles throughout the life of the plant.

Question 36

How are cellulose microfibrils arranged in young plant cells?

Answer 36

Cellulose microfibrils are arranged in parallel formation in the side walls of a young cell.

Question 37

What happens to a cell when internal pressures increase?

Answer 37

The cell elongates as microfibrils in the side walls spread apart due to internal pressures.

Question 38

What prevents a cell from growing in width?

Answer 38

The crisscross pattern of end-wall microfibrils prevents the cell from growing in width.

Question 39

What occurs when a cell reaches its maximum length?

Answer 39

Secondary wall thickening prevents further growth in the cell's length.

Question 40

How do most plant cells grow?

Answer 40

Most plant cells grow in a specific direction, dictated by the arrangement of cellulose microfibrils in their walls.

Question 41

What happens to a cell's walls when it enlarges?

Answer 41

The cell's walls temporarily soften, and bonds between side-wall microfibrils are loosened.

Question 42

What role does water uptake play in cell enlargement?

Answer 42

Cytoplasmic swelling occurs due to water uptake, which helps spread apart cellulose threads.

Question 43

Why do cells primarily grow in length?

Answer 43

Cells grow in length because the interwoven microfibrils in end walls do not allow similar stretching.

Question 44

What is the result of thickening in plant parts?

Answer 44

Thickening of plant parts results from a different growth process that will be discussed later.

Question 45

Where is the root's apical meristem located?

Answer 45

The root's apical meristem is the U-shaped area a short distance from the tip.

Question 46

What stages are involved in the division of nuclei during mitosis?

Answer 46

The stages are: (a) prophase, (b) metaphase, (c) anaphase, and (d) telophase.

Question 47

What happens at the end of mitosis?

Answer 47

Two daughter cells are formed.