1) Cell Structure

Question 1

What is resolution ?

Answer 1

ability to distinguish between 2 objects very close together

Question 2

what is magnification ?

Answer 2

number of times greater that an image is than the actual object

Question 2

compare the resolution of a light microscope with an electron microscope

Answer 2

light microscope = 200 nm
electron microscope = 0.2 nm

Question 3

compare the magnification of a light microscope with an electron microscope

Answer 3

light microscope = upto 1500
electron microscope = upto 500,000

Question 4

compare the radiation used of a light microscope with an electron microscope

Answer 4

light microscope = light rays
electron microscope = beam of electrons

Question 5

size and function of the cell surface membrane

Answer 5

(7nm)
- controls the movement of substances into and out of the cell
- cell signalling
- cell recognition
- cell to cell adhesion
- protects organelles from damage/pathogens (BARRIER BETWEEN CYTOPLASM & EXTERNAL ENV)

Question 6

function of the nucleus

Answer 6

• contains DNA
• coding for the synthesis of proteins

Question 7

structure & function of the rough ER

Answer 7

• covered with ribosomes.
• transport PROTEINS synthesised on the ribosomes.

Question 8

structure & function of the smooth ER

Answer 8

• no ribosomes.
• synthesises and transports LIPID molecules. (membrane, vesicles formed, cisternae)

Question 9

function of the golgi body

Answer 9

• synthesises glycoproteins.
• packages proteins for export from the cell.

Question 10

function of the mitochondria

Answer 10

produces ATP (adenosine triphosphate) by aerobic respiration

Question 11

location and function of ribosomes

Answer 11

• free in the cytoplasm / attached to the Rough ER.
• site of protein synthesis.

Question 12

where are 70S ribosomes found ?

Answer 12

Prokaryotes (chloroplasts, mitochondria, bacteria)

Question 13

where are 80S ribosomes found ?

Answer 13

Eukaryotes

Question 14

function of lysosomes

Answer 14

(in cytoplasm) digests unwanted materials and worn-out organelles

Question 15

function of microtubules

Answer 15

(in cytoplasm) involved in the movement of organelles

Question 16

location of centrioles

Answer 16

• animal cells
• next to the nucleus
• region called centrosome

Question 17

structure & function of centrioles

Answer 17

• made of protein microtubules
• formation of the spindle during nuclear division

Question 18

function of chloroplasts

Answer 18

• contain chlorophyll
• site of photosynthesis

Question 19

function of cell wall

Answer 19

• supports the plant cell and maintains its shape

Question 20

what is the cell wall made of in plants / fungi / bacteria ?

Answer 20

plants - cellulose
fungi - chitin
bacteria - peptidoglycan

Question 21

what is the plasmodesmata ?

Answer 21

pores in the cell wall

Question 22

function of the plasmodesmata

Answer 22

allows movement of materials between cells

Question 23

function of the vacuole

Answer 23

• holds water
• contains various solutes (sugars, minerals, salts, pigments)

Question 24

what is the membrane that surrounds the vacuole?

Answer 24

tonoplast

Question 25

function of the tonoplast

Answer 25

controls exchange of materials between the vacuole and the cytoplasm

Question 26

give 5 differences between animal and plant cells

Answer 26

- plant cells have cellulose cell walls, animal cells do not. - plant cells have chloroplasts, animal cells do not. - plants cells have a large permanent vacuole, animal cells do not. - plant cells do not have a centrosome but animal cells do. - carbohydrate storage product in plant cells is starch, whereas in animal cells it's glycogen

Question 27

what is the general size of a prokaryotic bacterial cell?

Answer 27

1-5 micrometres diameter

Question 28

what is the function of the flagellum

Answer 28

locomotion

Question 29

function of the capsule

Answer 29

additional protection

Question 30

what is a plasmid

Answer 30

a small circle of DNA

Question 31

function of pilli

Answer 31

for attachment to other cells or surfaces ; involved in sexual reproduction

Question 32

difference between DNA in eukaryotes & prokaryotes

Answer 32

--> eukaryotes - it has proteins attached and is linear. --> prokaryotes - naked and is circular

Question 33

give 5 differences between Eukaryotic cells & Prokaryotic cells

Answer 33

- eukaryotic are large , prokaryotic are small. - eukaryotic have a nucleus, prokaryotic do not. - eukaryotic has linear DNA, prokaryotic has circular DNA. - eukaryotic cell wall is made of cellulose, prokaryotic is made of peptidoglycan. eukaryotic has membrane bound organelles, prokaryotic does not. - eukaryotic has 80S ribosomes, prokaryotic has 70S ribosomes.

Question 34

what does peptidoglycan contain?

Answer 34

peptides/amino acids

Question 35

list 3 main features of a virus

Answer 35

- non-cellular - has nucleic acid core (DNA/RNA) - a capsid made of protein

Question 36

what is the envelope of viruses made of ?

Answer 36

phospholipids

Question 37

convert 1 mm into micrometres

Answer 37

1 x 1000 = 1000 micrometres

Question 38

convert 1 micrometre into nanometres

Answer 38

1 x 1000 = 1000 nanometres

Question 39

state 3 organelles that have a double membrane

Answer 39

- mitochondria - chloroplast - nucleus

Question 40

how is the structure of the cell surface membrane a fluid mosaic ?

Answer 40

fluid : phospholipid molecules diffuse/ move about mosaic : protein scattered