Chapter 7 Introduction to Cell Physiology

Chapter 7  Introduction to Cell Physiology

Complete Chapter Questions And Answers
 

Sample Questions

1.
A researcher is studying chromosomal disorders. What part of the human cell would the researcher be interested in studying?
A)
Cytoplasm
B)
Membrane
C)
Nucleus
D)
Organelles
Ans:
C

Feedback:

The nucleus of a cell contains all of the genetic material that is necessary for cell reproduction. The nucleus also contains genes or sequences of deoxyribonucleic acid (DNA). Genes are responsible for the formation of messenger ribonucleic acid (mRNA) and transcription RNA, which are involved in production of proteins unique to the cells. This is the area where chromosomal disorders originate. The cell cytoplasm lies within the cell membrane and is the site of activities of cellular metabolism and special cellular functions. The organelles are contained within the cytoplasm and are structures with specific functions. They include the mitochondria, endoplasmic reticulum, free ribosomes, Golgi apparatus, and lysosomes. The membrane is a thin barrier, which separates the intracellular fluid from the extracellular fluid and is essential for cellular integrity; it also maintains cell homeostasis.

2.
Which of these body cells has the greatest number of mitochondria?
A)
Tibia bone cells
B)
Breast tissue
C)
Cardiac muscle
D)
Subcutaneous skin
Ans:
C

Feedback:

Mitochondria are very abundant in cells that consume energy. The cardiac muscle cells, which must work continually to keep the heart contracting, contain a great number of mitochondria. Milk-producing cells in breast tissue, which are normally dormant, contain very few. Cells of bone and of subcutaneous tissue do not consume a great deal of energy; therefore, they have smaller numbers of mitochondria than cardiac muscle.

3.
When hormones, formed within the cell, move across the cell membrane, the process is called what?
A)
Endocytosis
B)
Exocytosis
C)
Phagocytosis
D)
Pinocytosis
Ans:
B

Feedback:

Exocytosis is the movement of substances such as waste products, hormones, and neurotransmitters out of the cell. Pinocytosis is the movement of nutrients and needed substances into the cell through specific receptors on the cell surface. Phagocytosis involves the destruction of engulfed proteins or bacteria. Endocytosis involves incorporation of material into the cell.

4.
What substances move freely in and out of a cell by diffusion?
A)
Electrolytes
B)
Enzymes
C)
Hormones
D)
Proteins
Ans:
A

Feedback:

Sodium, potassium, calcium, carbonate, oxygen, bicarbonate, and water move freely in and out of cells. These substances move through channels or pores in the cell membrane through movement from a region of higher concentration to a region of lower concentration. Hormones, enzymes, and proteins are considered carriers. If a substance cannot move freely on its own, it may attach itself to another carrier to be diffused.

5.
There can be interference with cancer chemotherapy in what phase of the cell cycle?
A)
G0 phase
B)
G1 phase
C)
G2 phase
D)
S phase
Ans:
A

Feedback:

During the G0 phase, the cell is stable. Cells in this phase can interfere with cancer chemotherapy because these drugs usually work on actively dividing cells, leaving resting cells mostly untouched. When the resting cells are stimulated to become active and regenerate, the cancer can return. This is the reason that cancer chemotherapy regimens are complicated and extended over a period of time. In the G1 phase, a cell is stimulated to emerge from its resting phase. During this time, the cell synthesizes the substances needed for DNA formation. The S phase involves the actual synthesis of DNA, and during the G2 phase, the cell produces all the substances that are required for the manufacture of the mitotic spindles.