Topic 1.2 - Cell Biology

Question 1

What are prokaryotic cells?

Answer 1

Prokaryotes are organisms whose cells lack a nucleus (‘pro’ = before ; ‘karyon’ = nucleus)

Question 2

What kingdom do prokaryotic cells belong to?

Answer 2

Monera and have been further classified into two distinct domains

Question 3

What 2 domains are prokaryotic cells classified as?

Answer 3

• Archaebacteria – found in extreme environments like high temperatures, salt concentrations or pH (i.e. extremophiles)
• Eubacteria – traditional bacteria including most known pathogenic forms (e.g. E. coli, S. aureus, etc.)

Question 4

9 main features in prokaryotic cells:

Answer 4

Cytoplasm
Nucleoid
Plasmids 
Ribosomes 
Cell membrane
Cell wall 
Slime capsule 
Flagella
Pili

Question 5

What is binary fission?

Answer 5

A form of asexual reproduction used by prokaryotic cells

Question 6

Process of binary fission:

Answer 6

• The circular DNA is copied in response to a replication signal
• The two DNA loops attach to the membrane
• The membrane elongates and pinches off (cytokinesis), forming two cells

Question 7

How do prokaryotic cells divide?

Answer 7

Through binary fission

Question 8

What are eukaryotic cells?

Answer 8

Organisms whose cells contain a nucleus (‘eu’ = good / true ; ‘karyon’ = nucleus)

Question 9

Which has a more complex structure, prokaryote or eukaryote?

Answer 9

Eukaryotic cells

Question 10

Where were eukaryotic cells believed to evolve from?

Answer 10

From prokaryotic cells (via endosymbiosis)

Question 11

What are Eukaryotic cells are compartmentalized by?

Answer 11

Membrane-bound structures (organelles) that perform specific roles

Question 12

Eukaryotes can be divided into four distinct kingdoms:

Answer 12

Protista
Fungi
Plantae
Animalia

Question 13

3 universal organelles:

Answer 13

Ribosomes
Cytoskeleton
Plasma membrane

Question 14

9 Eukaryotic Organelles:

Answer 14

Nucleus
Endoplasmic Reticulum
Golgi Apparatus
Mitochondrion
Peroxisome
Centrosome
Ribosomes
Cytoskeleton
Plasma membrane

Question 15

3 organelles only in plant cells:

Answer 15

Chloroplast
Vacuole
Cell Wall

Question 16

Organelle only found in plant cells:

Answer 16

Lysosome

Question 17

6 Key features of a prokaryotic cell:

Answer 17

Pili 
Flagella 
Ribosomes 
Cell wall 
Shape 
Size

Question 18

6 Key features in an animal cell:

Answer 18

Nucleus
Mitochondria 
Golgi apparatus
Endoplasmic reticulum 
Ribosomes
Cytosol

Question 19

4 Key features of a plant cell:

Answer 19

Vacuole
Chloroplasts
Cell wall
Shape

Question 20

All bacteria share features common to every prokaryotic cell, what are they?

Answer 20

• They lack a nucleus and membrane-bound organelles
• They have circular DNA that is naked (not bound to protein)
• They have smaller ribosomes (70S)

Question 21

Different types of bacteria can be distinguished according to a number of characteristics, what are they?

Answer 21

Shape
Cell wall composition
Gaseous requirements
Nutritional patterns

Question 22

Prokaryotic cells and eukaryotic cells differ in a number of key features, including:

Answer 22

• DNA (composition and structure)
• Organelles (types present and relative sizes)
• Reproduction (mode differs according to chromosome structure)
• Average size (exceptions may exist)

Question 23

DNA in prokaryotes and eukaryotes:

Answer 23

P: DNA is naked. DNA is circular. Usually no introns
E: DNA bound to protein. DNA is linear. Usually has introns.

Question 24

Animal cells and plant cells are both types of eukaryotic cells and hence share many common features, including:

Answer 24

• DNA stored within a nucleus
• Larger ribosomes (80S in size)
• A variety of membrane-bound organelles (e.g. mitochondria, ER, golgi apparatus)