Studying Cells

Question 1

What is the function of the nucleus?

Answer 1

• contains genetic material
• DNA replication
• production of mRNA
• production of rRNA

Question 2

Describe the structure of the nucleus.

Answer 2

• nuclear envelope and pores
• chromatin
• nucleolus

Question 3

What is the function of the mitochondria.

Answer 3

• site of aerobic respiration
• ATP production

Question 4

Function of rough endoplasmic reticulum.

Answer 4

• encrusted in ribosomes
• site of protein synthesis
• transports and stores proteins within the cell

Question 5

Function of Golgi apparatus.

Answer 5

• modifies + packages proteins
• produces vesicles

Question 6

Function of lysosomes.

Answer 6

• digestive enzymes
• digest organelles

Question 7

Function of cell surface membrane.

Answer 7

• phospholipid bilayer
• controls what enters and exits cell
• can be folded in to increase surface area

Question 8

Function of chloroplasts.

Answer 8

• contain thylakoids
• stacked into granum
• site of photosynthesis

Question 9

Function of capsule.

Answer 9

• protects cell from immune systems
• aids bacteria sticking together

Question 10

Function of plasmid.

Answer 10

• circular DNA
• contains antibiotic resistant genes

Question 11

Function of cell wall.

Answer 11

• provides rigid shape
• stops osmotic lysis

Question 12

Role of organelles in production, transport and release of proteins in a eukaryotic cell.

Answer 12

• DNA is code
• ribosomes on RER produce protein
• mitochondria produce ATP
• Golgi package/modify
• vesicles transport
• vesicles fuse with cell-surface-membrane

Question 13

Function of smooth endoplasmic reticulum.

Answer 13

• site of lipid synthesis

Question 14

Function of flagellum.

Answer 14

• allows movement

Question 15

Contrast eukaryotic and prokaryotic.

Answer 15

comparisons =
- nucleotide structure identical
- joined by phosphodiester bonds

contrasts =
- eukaryotic DNA is longer, prokaryotic shorter
- eukaryotic DNA contain introns, prokaryotic DNA doesn’t
- eukaryotic linear, prokaryotic circular
- eukaryotic histone, prokaryotic no histone

Question 16

Advantages of using TEM rather than SEM..

Answer 16

• higher resolution
• higher magnification
• allows internal details to be seen

Question 17

Advantage of using SEM rather than a TEM…

Answer 17

• thin sections do not need to be prepared
• shows surface of specimen
• can have 3D images

Question 18

What is the function of the ribosomes?

Answer 18

• site of protein synthesis

Question 19

Advantages and disadvantaged of using a TEM.

Answer 19

advantages =
- small objects can be seen
- TEM has high resolution
- electron wavelength shorter

disadvantages =
- cannot look at living cells
- must be in a vacuum
- must cut section

Question 20

Explain why the solution was =
isotonic
ice cold
buffered

Answer 20

• prevents osmosis
• reduce enzyme activity
• maintain constant pH

Question 21

Describe cell fractionation and centrifugation.

Answer 21

• homogenise cells to break cell surface membrane and release organelles
• filter to remove debris
  keep solution isotonic, ice cold and buffered
• creates supernatant
• centrifuge at higher speeds for lightest organelles