Cell Ultrastructure Q&A

BioKnowledgy Quick Quiz from 2.1 to 2.3

Which of the following is a characteristic of organelles?

They are sub-cellular structures

When viewing an exocrine cell of the pancreas using a light microscope which structures would NOT be visible?
I. The rough endoplasmic reticulum (rER)
II. Mitochondria
III. Nucleus
IV. 80s ribosomes

I (rER) and IV (80s ribosomes) only

Which of the following structures are present in BOTH plant and animal cells?
I. Cell wall
II. Chloroplast
III. Mitochondria

III (Mitochondria) only

In viewing an electron micrograph of a cell, ribosomes, pili and a single circular chromosome are observed. What other structure is likely to be present?

A plasmid

By what process do most bacteria divide?

Binary fission

The electron micrograph below shows an image of a cell.
a) Identify the structures labeled A and B in the electron micrograph above and state ONE function of each.

A.
Name: Flagella
Function: Used for locomotion / beats in whip-like action to propel cell
B.
Name: Pili
Function: Used for adhesion to another cell / transfer of genetic material between cells

The electron micrograph below shows an image of a cell.
b) Deduce which type of cell is shown in the diagram, giving reasons for your answer.

Bacteria / prokaryote. We know this because it has no mitochondria/membrane bound organelles or as there are pili present.

7a. Draw and label the ultrastructure of a pancreatic exocrine cell as seen when using an electron microscope.

A pancreatic exocrine cell is a eukaryotic animal cell.
Must include:
Plasma membrane (a single line around)
Nucleus (with double membrane and pores)
Mitochondria (with double membrane, half the nucleus, with inner folds)
Rough rER (multi-folded, with dots on)
Golgi apparatus (enclosed sacks with evidence of vesicle formation)
Ribosomes (small circles in cytoplasm and on rER)

7b. State ONE function for each of the following organelles
i. Ribosomes
ii. Rough endoplasmic reticulum
iii. Golgi apparatus

i. Protein synthesis (or translation, proteins, produces polypeptides)
ii. Synthesis of proteins for secretion (or support ribosomes, site of protein synthesis, folding of polypeptides)
iii. Formation of vesicles for exocytosis (or processing of proteins, forms lysosomes, produces glycoproteins)