2.1.1 cell structure

Question 1

name functions of the cytoskeleton. (6)

Answer 1

• provides mechanical support for the cell
• holds organelles in place
• enable cell to cell signalling
• forms mitotic and meiotic spindle fibres so chromosomes can move
• forms tracks for motor proteins
• allows changing of cell shape eg cytokinesis

Question 2

how does the cytoskeleton move organelles around the cell?

Answer 2

• using microtubules or motor proteins

Question 3

what’s the function of the nucleus?

Answer 3

• stores the cells DNA
• controls cells activities

Question 4

what’s the role of the rough endoplasmic reticulum? (2)

Answer 4

• folds and processes proteins made at the ribosome
• transports substances through the cisternae

Question 5

function of smooth endoplasmic reticulum ?

Answer 5

• process and synthesise lipids

Question 6

function of lysosome ?

Answer 6

• has hydrolitic enzymes to digest dead cells, pathogens and foreign objects

Question 7

how is a protein prepared and secreted after translation? (7)

Answer 7

• transport vesicle from RER
• to the Golgi body
• for modification
• then packaged into a secretory vesicle
• secretory vesicle moves along the cytoskeleton
• it fuses with the cell surface membrane
• then secreted by exocytosis

Question 8

what is the role of ribosomes

Answer 8

• site of protein synthesis

Question 9

what is the role of the cellulose cell wall? (2)

Answer 9

• supports plant cells and prevents it from bursting when they are turgid
• allow solutions to pass through since they are permeable

Question 10

what is the role of the flagella?

Answer 10

• tail-like structure that help cells move

Question 11

what’s the role of the nucleolus?

Answer 11

• where ribosomes are made

Question 12

what is the role of the centrioles?

Answer 12

• separate chromosomes during cell division
• form the cilia and undulipodia

Question 13

what is the role of the nuclear envelope?

Answer 13

• separates contents of the nucleus from the rest of the cell

Question 14

what is the role of the golgi body? (2)

Answer 14

• makes lysosomes
• modifies and packages proteins and lipids into vesicles

Question 15

what is the role of the mitochondria ?

Answer 15

• site of aerobic respiration, producing ATP

Question 16

what is the role of chloroplasts?

Answer 16

• site of photosynthesis

Question 17

what’s the role of the plasma membrane? (6)

Answer 17

• regulates the movement of substances into or out of a cell
• enables cell to cell signalling
• creates concentration gradients
• enables cell to cell recognition
• compartmentalisation: a barrier between the cell contents and the external environment
• site of chemical reactions

Question 18

what is the role of the vacuole?

Answer 18

• maintains cell stability, by keeping the cell turgid, thus supporting the whole cell

Question 19

how do eukaryotic cells divide?
what type of reproduction is this

Answer 19

• by mitosis or meiosis
  -mitosis is asexual , and meiosis is sexual reproduction

Question 20

how do prokaryotic cells divide?
what type of reproduction is this?

Answer 20

• by binary fission
• asexual reproduction

Question 21

do eukaryotic cells have membrane bound organelles?

Answer 21

yes

Question 22

do prokaryotic cells have membrane bound organelles?

Answer 22

no

Question 23

describe the cells genetic material in eukaryotic cells? (3)

Answer 23

• in the nucleus
• linear DNA
• associated with proteins

Question 24

describe the cells genetic material in prokaryotic cells (2)

Answer 24

• in chromosomal DNA or plasmids
• no protein association

Question 25

what is a prokaryotic cell wall made of?

Answer 25

- peptidoglycan

Question 26

what is a eukaryotic cell wall made of if it’s present?

Answer 26

- cellulose (plants) - chitin (fungi)

Question 27

do eukaryotic cells have a cytoskeleton?

Answer 27

yes

Question 28

do prokaryotic cells have a cytoskeleton?

Answer 28

- no. - if they do, it’s very simple

Question 29

are eukaryotic cells multicellular or unicellular?

Answer 29

- often multicellular

Question 30

are prokaryotic cells multicellular or unicellular?

Answer 30

- always unicellular

Question 31

do prokaryotic cells have a true nucleus?

Answer 31

- no, DNA kept in plasmids

Question 32

do eukaryotic cells have a nucleus?

Answer 32

- yes, encased with a nuclear envelope

Question 33

similarities between eukaryotes and prokaryotes (3)

Answer 33

- both have ribosomes - both have some form of DNA - both have cytoplasm and a plasma membrane

Question 34

what is the role of the nuclear pores? (1)

Answer 34

- allows movement of molecules in and out of the cell

Question 35

role of the cilia / undulipodia ? (3)

Answer 35

- has receptors to allow the cell to detect signals about its environment - sperm has undulipodia to move - moves substances along the cell surface eg mucus

Question 36

what is differential staining?

Answer 36

- when different dyes are used to differentiate between different cells or orangelles.

Question 37

why do we stain in light microscopy?

Answer 37

- so internal structures are more visible - to increase contrast - to distinguish between cell types