cells

Question 1

Give one piece of evidence that supports the theory that mitochondria evolved from prokaryotic cells.

Answer 1

Circular DNA / smaller/70S ribosomes / no introns / no histones/proteins associated with DNA;

Question 2

Explain the arrangement of phospholipids in a cell-surface membrane.

Answer 2

Bilayer

OR

Water is present inside and outside a cell;

Accept annotated diagram for ‘bilayer’

Accept cytoplasm/tissue fluid for water

Accept for two marks, annotated diagram of bilayer with water labelled on each side

2. Hydrophobic (fatty acid) tails point away/are repelled from water

OR

Hydrophilic (phosphate) heads point to/are in/are attracted to water;

Question 3

What is the advantage to cells of having mitochondria

Answer 3

Able to respire aerobically;

2. So make (more) ATP/ release (more) energy

Question 4

Cells that secrete enzymes contain a lot of rough endoplasmic reticulum (RER) and a large Golgi apparatus.

(i) Describe how the RER is involved in the production of enzymes.

Answer 4

Rough endoplasmic reticulum has) ribosomes;

accept “contains / stores”

2. To make protein (which an enzyme is)

Question 5

Describe how the Golgi apparatus is involved in the secretion of enzymes.

Answer 5

Golgi apparatus) modifies (protein)

Question 6

Some cells lining the bronchi of the lungs secrete large amounts of mucus. Mucus contains protein.

Name one organelle that you would expect to find in large numbers in a mucus-secreting cell and describe its role in the production of mucus.

Organelle______________________________________________________

Description of role

Answer 6

Organelle named; Function in protein production / secretion;

Function must be for organelle named

Incorrect organelle = 0

eg

1. Golgi (apparatus);
2. Accept smooth endoplasmic reticulum
3. Package / process proteins;

OR

3. Rough endoplasmic reticulum / ribosomes;
4. Accept alternative correct functions of rough endoplasmic reticulum. ER / RER is insufficient
5. Accept folding polypeptide / protein
6. Make polypeptide / protein / forming peptide bonds;

OR

5. Mitochondria;
6. Release of energy / make ATP;
7. Reject produce / make energy
8. Accept produce energy in the form of ATP

OR

7. Vesicles;
8. Secretion / transport of protein;

Question 7

Explain how the inner membrane is adapted to its function in organelle A. mitochondria

Answer 7

increased surface area;
for respiration / enzymes;

Question 8

Give two ways in which the structure of this bacterium is similar to the structure of a cell lining the human small intestine.

1. ____________________________________________________________

______________________________________________________________

2. ____________________________________________________________

______________________________________________________________

(2)

(ii) Give two ways in which the structure of this bacterium differs from the structure of a cell lining the human small intestine.

Answer 8

cytoplasm;
ribosomes;
phospholipid membranes / cell membrane / semipermeable
membrane;

(accept folded membrane for two marks)

2 max

(ii) (it = bacterium)
cell wall;
capsule;
flagellum;
mesosome;
no nucleus / nuclear membrane / DNA free;
no mitochondria;

(accept ‘no membrane-bound organelles’ if neither nucleus nor mitochondria mark scored)

no microvilli;
no Golgi;
no ER;

Question 9

The thyroid gland is an organ in the neck. The diagram shows the process in which epithelial cells from the thyroid gland make and secrete a protein called thyroglobulin.

the process by which thyroglobulin is secreted from the cell at C.

Answer 9

exocytosis

Question 10

Eukaryotic cells produce and release proteins.

Outline the role of organelles in the production, transport and release of proteins from eukaryotic cells.

Do not include details of transcription and translation in your answer.

__________________________________________________________

Answer 10

v DNA in nucleus is code (for protein);

2. Ribosomes/rough endoplasmic reticulum produce (protein);

Accept rER for ‘rough endoplasmic reticulum’

3. Mitochondria produce ATP (for protein synthesis);
4. Golgi apparatus package/modify

Vesicles transport

OR

Rough endoplasmic reticulum transports;

6. (Vesicles) fuse with cell(-surface) membrane;