B3 - Cell Structure

Question 1

What does the cell surface membrane do

Answer 1

Controls what enters and leaves the cell

Question 2

What is the nucleus for

Answer 2

Stores DNA and controls the cell. Nucleolus makes ribosomes

Question 3

What is the job of the mitochondria

Answer 3

Releases energy by aerobic respiration (makes ATP)

Question 4

What do chloroplasts do

Answer 4

Photosynthesis - absorb light to make glucose

Question 5

What is the golgi apparatus

Answer 5

Modifies and packages proteins and lipids into vesicles

Question 6

What do lysosomes do

Answer 6

Break down waste using lysozymes

Question 7

What do ribosomes do

Answer 7

Make proteins

Question 8

What does the Rough ER do

Answer 8

Makes and transport£ proteins (it has ribosomes)

Question 9

What does the smooth ER do

Answer 9

Makes and processes lipids and carbohydrates

Question 10

What is the cell walls function

Answer 10

Supports and strengthens cell. Maintains turgidity

Question 11

What are cell walls made out of

Answer 11

Cellulose or chitin

Question 12

What is the vacuole for

Answer 12

Maintains turgidity and stores sap

Question 13

What is cell specialisation

Answer 13

When a cell develops structures to do a specific job

Question 14

What is a tissue

Answer 14

A group of specialised cells with a similar function

Question 15

What is an organ

Answer 15

A group of tissues working together to perform a function

Question 16

What is an organ system

Answer 16

A group of organs working together

Question 17

How do prokaryotic cells differ from eukaryotic cells in size

Answer 17

Prokaryotes are much smaller

Question 18

Do prokaryotes have membrane bound organelles?

Answer 18

No

Question 19

Do prokaryotes have ribsomes

Answer 19

Yes, smaller ones

Question 20

Do prokaryotes have a nucleus

Answer 20

No they have a single circular DNA molecule that is free in the cytoplasm

Question 21

Is prokaryotic DNA associated with proteins

Answer 21

No

Question 22

What is a prokaryote cell wall madenof

Answer 22

Murein

Question 23

What are plasmids

Answer 23

Small DNA molecules found in some prokaryotes

Question 24

What is the function of the flagella

Answer 24

Helps the cell move

Question 25

Function of the capsule in prokaryotes

Answer 25

Helps protect the cell and allows it to stick to surfaces

Question 26

Viruses are _ & _

Answer 26

Acellular and non-living

Question 27

Structure of a virus particle includes:

Answer 27

Attachment proteins, capsid, and genetic material

Question 28

What do attachment proteins do

Answer 28

Allow the virus to attack to host cells

Question 29

Limitations of an optical light microscope

Answer 29

Low resolution (200nm) and magnification (x1500)

Question 30

Advantage of a light microscope

Answer 30

Can view live specimen Cheap, portable, colour images

Question 31

What does a TEM show

Answer 31

A 2D image of the internal structure

Question 32

What does an SEM show

Answer 32

A 3D image of the surface

Question 33

Principles of a TEM

Answer 33

Electrons pass through. Denser areas absorb more electrons and appear darker

Question 34

Principles of an SEM

Answer 34

Electrons bounce of surface, forming a 3D image

Question 35

Limitations of SEM

Answer 35

Specimen must be coated in metal

Question 36

Limitations of TEM

Answer 36

Specimen must be dead, only works in a vacuum

Question 37

What is magnification

Answer 37

How much larger an image is compared to the real object

Question 38

What is resolution

Answer 38

The ability to distinguish between 2 close points as seperate

Question 39

Magnification formula

Answer 39

Image size / actual size

Question 40

What are artefacts

Answer 40

Features that appear due to preparation techniques, not naturally present

Question 41

What is the principle of cell fractionation

Answer 41

Cells are broken open and organelles are separated by density using centrifugation

Question 42

What are the main steps in cell fractionation

Answer 42

Homegenisation -> Filtration -> Ultracentrifugation

Question 43

What happens in ultracentrifugation

Answer 43

Cell fragments are spun at increasing speeds, heavier organelles (e.g nucleus) form pellets first

Question 44

Stages of the cell cycles

Answer 44

Interphase (Mitosis) Prophase Metaphase Anaphase Telophase Cytokinesis

Question 45

What happens in Interphase

Answer 45

DNA Replicates, cell grows, organelles replicate

Question 46

What happens in Prophase

Answer 46

Chromosomes condense, spindle fibres form, nuclear envelope breaks down

Question 47

What happens in metaphase

Answer 47

Chromosomes line up on cell equator Spindle fibres attack to centromeres

Question 48

What happens in anaphase

Answer 48

Spindle fibres shorten, pulling sister chromatids to opposite sides

Question 49

What happens in telophase

Answer 49

Chromatids uncoil, nuclear envelope forms around chromosomes

Question 50

What happens in cytokinesis

Answer 50

Cytoplasm splits, 2 new identical daughter cells formed

Question 51

What do spindle fibres do

Answer 51

Attack to centromeres and pull chromatids apart during anaphase

Question 52

What happens when mitosis is uncontrolled

Answer 52

Formation of tumors and cancers

Question 53

How do some cancer drugs work

Answer 53

By disrupting cell cycle and preventing mitosis

Question 54

How do prokaryotes divide

Answer 54

Via binary fission

Question 55

3 steps of binary fission

Answer 55

Circular DNA Replicates Plasmids replicate Cytoplasm divides

Question 57

Do viruses undergo cell division?

Answer 57

No they're non living

Question 58

How do viruses replicate

Answer 58

They Inject nucleic acid into host cells and produce new virus particles

Question 59

What does each daughter cells receive in binary fission

Answer 59

One copy of circular DNA