Cells

Question 1

The cell membrane is mainly composed of:
a. a single layer of protein molecules
b. a protein bilayer
c. a phospholipid bilayer
d. a polysaccharide bilayer

Answer 1

c.
a phospholipid bilayer

Question 2

Which of the following is not found in the nucleus of the cell?
a. centrioles
b. chromosomes
c. DNA

Answer 2

a.
centrioles

Question 3

Which organelle is the site for ATP production?
a. nucleolus
b. mitochondrion
c. Golgi complex
d. ribosome

Answer 3

b.
mitochondrion

Question 4

What is the function of the rough endoplasmic reticulum in the mammalian cell?
a. storage of lysosomal enzymes
b. synthesis and transport of proteins
c. synthesis of glucose
d. production of ATP

Answer 4

b.
synthesis and transport of proteins

Question 5

During which stage of mitosis do the chromosomes line up in the middle of the cell?
a. prophase
b. anaphase
c. metaphase

Answer 5

c.
metaphase

Question 6

When does ‘crossing-over’ take place during meiosis?
a. metaphase
b. prophase
c. anaphase
d. telophase

Answer 6

b.
prophase

Question 7

Fluid that has a lower osmotic pressure than that of plasma is said to be:
a. hypotonic
b. isotonic
c. hypertonic d. isometric

Answer 7

a.
hypotonic

Question 8

Which of the following cations is in a relatively higher concentration in the intracellular fluid than in the extracellular fluid?
a. potassium
b. iodine c. sodium
d. chloride

Answer 8

a.
potassium

Question 9

Which of the following is not an example of a structural protein?
a. collagen
b. enzymes
c. elastin
d. keratin

Answer 9

b.
enzymes

Question 10

Which of the following statements is the least accurate?
a. an acidic solution has a pH of below 7
b. the pH scale is a measure of a solution’s hydrogen ion
content
c. an alkaline substance releases hydrogen ions when dis-
solved in a solution
d. the pH of body fluids is 7.35

Answer 10

c.
an alkaline substance releases hydrogen ions when dis-
solved in a solution

Question 11

Explain what is meant by the term ‘selectively permeable’

Answer 11

Some substances are able to pass through the membrane, while other substances are not able to pass through.

Question 12

Describe the role of mitochondria in an animal cell

Answer 12

Mitochondria produce the energy necessary for the cell’s survival and functioning.
Through a series of chemical reactions, mitochondria break down glucose into an energy molecule known as adenosine triphosphate (ATP),
which is used to fuel various other cellular processes.

Question 13

What are the differences between mitosis and meiosis?

Answer 13

• Mitosis occurs in non-reproductive cells, or somatic cells
• Produces two genetically identical “daughter” cells from a single “parent” cell,
• Meiosis occurs in the cells that participate in sexual reproduction, or germ cells.
• Produces cells that are genetically unique from the parent and contain only half as much DNA.

Question 14

Describe the differences between osmosis and diffusion

Answer 14

In diffusion, particles move from an area of higher concentration to one of lower concentration until equilibrium is reached.
In osmosis, a semipermeable membrane is present, so only the solvent molecules are free to move to equalize concentration