Core Concept: Cell structure and organisation

Question 1

Define organelle

Answer 1

a specialised structure with a specific function inside a cell

Question 2

Define Eukaryote

Answer 2

an organism containing cells that have membrane-bound organelles with DNA in chromosomes within the nucleus

Question 3

12 components of a generalised animal cell

Answer 3

cell membrane
cytoplasm
smooth endoplasmic reticulum
rough endoplasmic reticulum
golgi body
ribosomes
mitochondria
nucleus
nucleolous
nuclear envelope
nuclear pore
DNA

Question 4

16 components of a generalised plant cell

Answer 4

cell wall
cell membrane
cytoplasm
smooth endoplasmic reticulum
rough endoplasmic reticulum
golgi body
ribosomes
chloroplasts
Mitochondria
vacuole
tonoplast
nucleus
nucleolous
DNA
nuclear envelope
nuclear pore

Question 5

From smallest to biggest order nanometre, kilometre, micrometre, metre and millimetre.

Answer 5

nanometre - micrometre - millimetre - metre - kilometre

Question 6

What size is the nucleus

Answer 6

10-20 micrometres

Question 7

Describe the components of the nucleus and their function

3 areas 5 components

Answer 7

2 membranes called the nuclear envelope with nuclear pores - allow movement of rRNA and mRNA out of the nucleus the outer membrane is continuous with the RER

neoplasm in the nucleaus which contains chromatin - coils of DNA bound to a protein it condenses into chromosomes

nucleolous - synthesises rRNA

Question 8

What is a mitochondrion comprised of

5 points

Answer 8

outer cell membrane
inner cell membrane/cristae
matrix
DNA
70s ribosomes

Question 9

Describe the membrane of the mitochondria and how it is adapted for its function

Answer 9

it has a double membrane which are seperated by the intermembrane space the inner membrane is folded inwards to form the cristae this allows for more surface area for more respiratory enzymes

Question 10

Describe the shape of a mitochondrion what is its function and how is it adapted for this

Answer 10

it is cylindrical it is the site of aerobic respiration producing ATP it has a higher surface area to volume ratio compared to a sphere it reduces the diffusion distance between te edge and the centre, making aerobic respiration more efficient.

Question 11

What size is a mitochondrion

Answer 11

1-10 micrometres

Question 12

7 components of a chloroplast

Answer 12

double membrane
granum
thylakoid
intergranal lamella
stroma
DNA
70s ribosomes

Question 13

In most plants, what cell has the highest concentration of Chloroplasts

Answer 13

Palisade mesophyll cells

Question 14

What is the endosymbiotic theory
And what evidence can suggest this

Answer 14

that eukaryotic cells once began as prokaryotic cells and a large cell englufed the mitochondria and chloroplast
they have. a double membrane and have their own 70s ribosomes and DNA so they can produce their own proteins and can replicate

Question 15

Describe the structure of the endoplasmic reticulum

Answer 15

elaborate system of parallel double membranes formimg a series of flattened sacs with Interconnected fluid filled spaces between them called cisterna

Question 16

What are the two types of endoplasmic reticulum and their function

Answer 16

Rough ER - has ribosomes on its outer surface and it folds the proteins made there also transports them to golgi
smooth ER - has no ribosomes on it it synthesises, transports and modifies lipids

Question 17

What cells will have an extensive endoplasmic reticulum

Answer 17

cells that store a high amount of carbohydrates, lipids or proteins like liver cells and secretory cells

Question 18

What is the function of a ribosome

Answer 18

site of proteins synthesis

Question 19

What is the different sizes of ribosomes and where would they be found

Answer 19

80s in eukaryotes
70s in prokayotes

Question 20

Describe the structure of a ribosome where it is assembled and what it is made of

Answer 20

large sub unit on top
small sub unit on the bottom
it is assembled in the nucleolous
and made of rRNA and proteins

Question 21

Where does the mRNA and tRNA attach on a ribosome

Answer 21

where there are two tRNA binding sites within
where the mRNA binds and is fed through

Question 22

What is the structure of the Golgi body

Answer 22

compact elaborate system of parallel double membranes formimg a series of flattened sacs called cisternae

Question 23

What are the functions of the Golgi body

Answer 23

Producing secretory enzymes packaged into secretory vesicles

secreting carbohydrates

producing glycoproteins

transporting and storing lipids

forming lysosomes

Question 24

What is a lysosome
And its function

Answer 24

single membrane fluid fillled vesicle containing digestive (hydrolytic) enzymes

they can contain and isolate harmful digestive enzymes from the rest of the cell these enzymes can digest material such as a white blood cell that has englufed a bacteria or food

Question 25

What is are centrioles And what is its function

Answer 25

two rings of microtubules making hollow cylinders positioned at right angles to each other during cell division they have a role in forming and controlling the spindle fibres

Question 26

What is a Vacuole And its function

Answer 26

fluid filled sac bound by a single membrane it contains cell sap, a solution containing amino acids,vitamins, minerals and glucose.

Question 27

What is a Tonoplast

Answer 27

The tonoplast is a stretchy membrane, and its main function is to protect the vacuole and isolate it from harmful substances. The tonoplast membrane controls ionic and osmotic movement in and around the cell.

Question 28

What is the structure of a plant cell wall

Answer 28

cellulose is held together in microfibrils which are aggregated into fibres, embedded in a polysaccharide matrix called pectin

Question 29

What are the functions of a plant cell wall | 3 points

Answer 29

Transport - the gaps in the cellulose fibres makes the cell wall fully permeable to water and minerals Mechanical strength - the microfibrils and thier laminated arrangement make the cell wall strong allowing the cell to be turgid and withstand high pressure potential communication between cells -cell walls have pits in which strands of cytoplasm called plasmodesmata pass

Question 30

What are the 2 pathways of water and minerals through the plant route What does each consist of

Answer 30

apoplast - moves through the cell wall until the casparian strip symplast - water and mineralls move through the cytoplasm and the plasmodesmata

Question 31

Differences between plant and animal cells | 6 points

Answer 31

plants have a perminent large vacuole - animals have a small tempory one plants have chloroplasts - animals dont plants have a cell wall - animals dont plants dont have centrioles - animals have centrioles plants have plasmodesmata - animals have no plasmodesmata plants have startch as an energy store - animals have glycogen as an energy store

Question 32

Define Prokaryote

Answer 32

a single-celled organism with no membrane bound organelles DNA is free in the cytoplasm

Question 33

Name 8 components of the generalised prokaryotic cell

Answer 33

flagellum cell membrane cytoplasm peptidoglycan cell wall mesosome plasmid DNA 70s ribosomes

Question 34

What components are in all prokaryotes | 5 points

Answer 34

peptidoglycan cell wall cell membrane DNA free in cytoplasm cytoplasm 70s ribosomes

Question 34

In eukaryotic and prokaryotic cells Compare the following: length, organelles, DNA, Nuclear envelope, plasmids, cell wall, chloroplasts, mitochondria, mesosome, and ribosomes

Answer 34

length - euk>Pro organelles - membrane bound in eukaryote not in prokaryotes DNA - combined with proteins in chromome eukaryotes but free in the cytoplasm in prokarytes nuclear envelope - in the eukaryote not in prokaryote plasmids - not in Eukaryote plasmids sometimes in Prokaryote cell wall - cellulose in plant and chitin in fungi cell wall (Eukaryotes) but in Prokaryote it is peptidoglycan chloroplasts - in plant Eukaryotes not in Prokaryotes mitochondria - present in eukaryotes not in prokaryotes mesosome - not in Eukaryote is in Prokaryote ribosomes - 80s in Eukaryotes 70s in prokaryotes

Question 35

Describe the structure of a virus

Answer 35

protein coat called a capsid and a strand of DNA or RNA if RNA its called a retro virus

Question 36

Is a virus living or non living provide an explanation

Answer 36

non living as it does not have any of the living characteristiccs

Question 37

Define tissue

Answer 37

group of cells with the same structure and function working together

Question 38

Name three tissue types

Answer 38

epithelium muscle connective

Question 38

Describe the structure of an epithelial tissue

Answer 38

forms a continuous layer covering the internal or external layers of the surfaces of the body no blood vessels but can have nerve endings the cells sit on a basement membrane (made of collagen and protein.

Question 38

What are the three types/shapes of epithelial tissue And where they are found

Answer 38

cuboid - one cell thick found in the proximal convuluted tubule Columnar - eleongated cells with cilia are in oviduct and trachea squamous - flattened cells on the basement membrane form the walls of the bowmans capsule and alveoli

Question 39

Name three types of muscle tissue And their features and functions | 3 points

Answer 39

smooth - spindle-shape unstriped involluntary tissues that can contract Rhythmically but less powerfully than skeletal found in skin, in walls of blood vessels, in digestive and respiratory tracts skeletal - long, striped and voluntary powerful contractions. they attatch to bone and generate locomotion they can tire. cardiac - striped, short and involuntary muscles only found in the heart that contract rhythmically without stimulation from hormones or nerves and it does not tire

Question 40

Describe the role of connective tissue

Answer 40

connects, supports or seperates tissues and organs it contains elastic and collagen fibres in an extracellular fluid or matrix between the fibres there is fat storing cells and immune system cells

Question 41

Define organ

Answer 41

a group of tissues in a structural unit working together and performing a specific function

Question 42

define system

Answer 42

a group of organs working together with with a particular role

Question 43

define organism

Answer 43

all systems of the body working together making an organism which is a discrete individual