a2.2- organelles (e + p)

Question 1

prokaryotes

Answer 1

organisms that do not have a true nucleus
DNA is not protected by the nucleus

Question 2

function of cell wall [2]

Answer 2

P
1. maintains shape
2. prevents bursting

Question 3

plasma membrane

Answer 3

E + P
semi-permeable and selective barrier surrounding the cell

Question 4

cytoplasm

Answer 4

E + P
internal fluid component of the cell

Question 5

bound ribosomes

Answer 5

E + P
- synthesises protein used OUTSIDE the cell

Question 6

free ribosomes

Answer 6

E + P
- synthesises protein used INSIDE the cell

Question 7

rough ER

Answer 7

E
starts the folding of polypeptide

Question 8

smooth ER

Answer 8

E
synthesises the phospholipid
> used in cell membrane + cholesterol

Question 9

cells with ERs…

Answer 9

undertake secretory activities
e.g. plasma cells, exocrine gland cells

Question 11

function of mitochondria

Answer 11

E
aerobic respiration
- needs increased conc. oxygen and glucose

Question 12

structure of mitochondria [2]

Answer 12

• double membrane
• inner membrane highly folded into internal cristae

Question 13

golgi apparatus

Answer 13

E
- modifies polypeptides into their functional state
- sorts, concentrates and packs proteins into vesicles
- exocytosis

Question 14

lysosome structure

Answer 14

E
- membranous sacs filled with hydrolytic enzymes

Question 15

lysosome function

Answer 15

• breakdown/hydrolysis of macromolecules
• contains lysozymes (digestive enzyme)

Question 16

plasmids

Answer 16

P
autonomous circular DNA molecules that may be transferred between bacteria (horizontal gene transfer)

Question 17

pili

Answer 17

P
hair like extensions that
1. enable adherence to surfaces (attachment pili)
2. mediate bacterial conjugation (sex pili)

Question 18

slime capsule

Answer 18

P
thick polysaccharide layer used for protection against desiccation (drying out) and phagocytosis

Question 19

vesicles

Answer 19

E + P
move substances in + out of cell
either to
1. within the cell (lysosomes)
2. plasma membrane out of cell
3. secretion to the outside of the cell (exostosis)

Question 20

compartmentalised because [3]

Answer 20

1. control concentration of chemicals needed
2. avoid enzymes
3. mRNA can be modified after transcription before it leaves the nucleus

Question 21

typical cells contain [2 + reason]

Answer 21

1. DNA as genetic material
2. cytoplasm
   - dissolve substances
   - carry out metabolic reactions

Question 22

DNA in prokaryote is…

Answer 22

naked + in a loop

Question 23

plasma membrane in a eukaryote

Answer 23

enclosing a compartmentalised cytoplasm with 80S ribosomes

Question 24

nucleus [5]

Answer 24

E
- with chromosomes made of DNA
- store genetic material as chromatin
- bound to histones
- contained in a double membrane with pores
- inner region called nucleolus: site of ribosome assembly

Question 25

eukaryotes has cytoskeleton of..

Answer 25

microtubules and microfilaments

Question 26

advantages of compartmentalisation in the cytoplasm

Answer 26

• concentration of metabolites and enzymes and the separation of incompatible biochemical processes
  eg. lysosomes and phagocycotic vacuoles

Question 27

plasma membrane composed of…

Answer 27

lipids

Question 28

structure of cytoskeleton

Answer 28

• filamentous scaffolding within the cytoplasm

Question 29

function of cytoskeleton [2]

Answer 29

• provides internal structure
• mediates intracellular transport
  less developed in prokaryotes

Question 30

peroxisome function

Answer 30

catalyses breakdown of toxic substances and other metabolites

Question 31

peroxisome structure

Answer 31

E
membranous sac containing a variety of catabolic enzymes

Question 32

centrioles function

Answer 32

E (X plant cells)
- microtubule organising centre
- arrangement of the mitotic spindle during cell division
- serve as anchor points for microtubules in the cytoplasm, cilia and flagella

Question 33

centriole structure

Answer 33

• paired cylindrical
  -shaped organelles composed of nine groups of three microtubules organised symmetry
• fibrous protein inside the cells

Question 34

chloroplast structure [2]

Answer 34

plant
- double membrane
- internal stacks of membranous discs (thylakoids)

Question 35

chloroplast function

Answer 35

site of photosynthesis- manufactured organic molecules are stored in various plastids

Question 36

cell wall structure

Answer 36

plant
- external outer covering made of cellulose
- not an organelle

Question 37

cell wall function [2]

Answer 37

• provides support and mechanical strength
• prevents excess water uptake

Question 38

plastids present in

Answer 38

plants

Question 39

cell wall present in

Answer 39

plants + fungi

Question 40

how do plant and fungi differ [3]

Answer 40

1. no chloroplasts
2. diff cell wall material
3. decomposers

Question 41

centrioles present in

Answer 41

animal

Question 42

cilia present in

Answer 42

animal + plant

Question 43

flagella present in

Answer 43

animal + plant

Question 44

vesicle’s journey

Answer 44

• formed in the rough ER
• received by Golgi apparatus
• Golgi apparatus forms vesicles that transport substances to membrane

Question 45

why is cell wall not an organelle

Answer 45

do not have a specific metabolic function