Cell Structure and Organisation

Question 1

How is the nucleus structured?

Answer 1

Surrounded by double membrane (nuclear envelope).
Has nuclear pores to allow movement of mRNA and nucleotides out.
Contains nucleoplasm.
Nucleolus- rRNA is produced.

Question 2

What can be found in the nucleoplasm ?

Answer 2

Chromatin- loosely coiled chromosomes of DNA + histone protein.

Question 3

What is formed by the outer nuclear membrane?

Answer 3

Endoplasmic reticulum

Question 4

What is the function of mitochondria (s. Mitochondrion)?

Answer 4

Aerobic respiration occurs to produce ATP.

Question 5

Where are many mitochondria found?

Answer 5

Muscle tissue for contraction and liver tissue which is metabolically active

Question 6

Structure of a mitochondrion-

Answer 6

Cristae- double membrane sac with highly folded inner membrane, increasing surface are.
Matrix-liquid containing enzymes for aerobic respiration
Ribosomes
Circular DNA- self replicating

Question 7

What are the two forms of endoplasmic reticulum and what are their functions?

Answer 7

Smooth- synthesises lipids

Rough- ribosomes are attached that synthesise proteins

Question 8

What is the structure of ER?

Answer 8

Consists of flattened sacs called cisternae which extend into cytoplasm and can link with the golgi body

Question 9

What is the function of the nucleus?

Answer 9

It contains the cell’s DNA which provides the code for protein synthesis. mRNA leaves via the nuclear pores carrying the code.

Question 10

How are ribosomes structured?

Answer 10

Very small not membrane-bound
Composed of 2 sub-units, large and small.
Come together around mRNA strand which fits into a groove

Question 11

What are ribosomes made of?

Answer 11

Protein and rRNA

Question 12

Where can ribosomes be found?

Answer 12

On RER or free in cytoplasm (called polysomes)

Question 13

What is ribosomes’ function?

Answer 13

Protein synthesis

Question 14

What is the golgi body (apparatus)?

Answer 14

A crescent shaped stack of flattened membrane-bound sacs called cisternae.

Question 15

What are the functions of the golgi body?

Answer 15

Chemically modifies proteins to form glycoproteins.

Stores and transports glycoproteins and lipids

Question 16

What is the first part of the golgi body process for glycoproteins?

Answer 16

Vesticles containing proteins formed by RER fuse at one end of golgi sacs (forming face)

Question 17

What are the second and third parts of the golgi body process for glycoproteins?

Answer 17

2. The protein is modified inside the cisternae.

3. Modified protein is budded off in a vesticle at other end of cisternae (maturing face)

Question 18

What is the final part of the golgi body process for glycoproteins?

Answer 18

The vesticle containing modified protein travels to cell’s outer plasma membrane where the protein is released via exocytosis

Question 19

What is the structure of plasma membrane?

Answer 19

Formed of a phospholipid bilayer with intrinsic and extrinsic proteins and other molecules embedded into it

Question 20

What are the 3 properties/functions of plasma membranes?

Answer 20

• Selectively permeable so controls substances going in and out.
• Maintains concentration difference of molecules on either side of the membrane.
• allows cell identification and adhesion

Question 21

Which two organelles can only be found in animal cells?

Answer 21

Lysosomes and centrioles

Question 22

Which 3 organelles can only be found in plants?

Answer 22

Chloroplasts, Vacuole with tonoplasts and Cellulose Cell Wall

Question 23

What are lysosomes?

Answer 23

Small vacuoles surrounded by a membrane formed by pieces of golgi apparatus pinched off the end.

Question 24

What is the function of lysosomes?

Answer 24

Break down worn out organelles and digest material taken in via phagocytosis

Question 25

What type of enzymes are within a lysosome?

Answer 25

Protein digesting

Question 26

What is the action of the lysosomes?

Answer 26

Material taken into cell by endocytosis and trapped in vacuole. Lysosomes fuse with vacuole membrane and release digestive enzymes, breaking down the material.

Question 27

What is the structure of centrioles?

Answer 27

Microtubules, lying at right angles to each other

Question 28

Where are centrioles located?

Answer 28

Centrosome just outside nucleus

Question 29

What is the fuction of centrioles?

Answer 29

Formation of spindle fibres during cell division

Question 30

What is the function of a plant cell's vacuole with a tonoplast?

Answer 30

Water and sap storage | Support

Question 31

Look at picture of chloroplast and cover up parts

Answer 31

Do it.

Question 32

What are a chloroplast's functions?

Answer 32

Photosynthesis site Traps light energy and uses it to produces carbohydrates from CO2 and H20 May also store starch and lipid

Question 33

How is a cellulose cell wall structured?

Answer 33

Composed of cellulose microfibrils Totally permeable TO WATER Has many plasmodesmata

Question 34

What are plasmodesmata and what are they for?

Answer 34

Pores that allow cytoplasm of adjacent cells to connect enabling substances to pass between cells

Question 35

What is the function of cellulose cell walls?

Answer 35

Stops cell bursting in dilute solution i.e. prevents osmotic lysis. Provides mechanical strength and support.

Question 36

What is a tissue?

Answer 36

A group of similar cells together carrying out the same function.

Question 37

How are epithelial tissue structured?

Answer 37

Continuous layer lining internal/external body surfaces No blood vessels but may have nerve endings Sit on basement membrane

Question 38

What is are the key properties of cuboidal epithelium?

Answer 38

Simplest form, cube shape and one cell thick

Question 39

Where is cuboidal epithelium found?

Answer 39

Kidney tubules and liver

Question 40

What are the key properties of columnar epithelium?

Answer 40

Elongated | Those that line tubes that substances move through will have more cilia

Question 41

Where can columnar epithelium be found?

Answer 41

Oviduct | Trachea

Question 42

How is squamous cell epithelium shaped and where are they found?

Answer 42

Flattened cells on basement membrane | Walls of alveoli

Question 43

What are the three epithelial tissues?

Answer 43

Cuboidal Columnar Squamous Cell

Question 44

What do microvilli do when on epithelial tissue?

Answer 44

Increase cell membrane surface area for absorption e.g. Small intestine

Question 45

What are the functions for epithelium tissues that have:- Mitochondria- Enzymes- Cilia-

Answer 45

ATP for active transport e.g. Ileum For digestion (small intestine) Cilia to trap and move particles e.g. respiratory traction

Question 46

How do you calculate magnification?

Answer 46

Image size divided by object size

Question 47

How do you calculate conversion factor?

Answer 47

Stage micrometer units divided by eyepiece units x 10

Question 48

What are the three muscle tissue types?

Answer 48

Striated/skeletal Cardiac Smooth

Question 49

What are the four properties of striated/skeletal muscle tissue?

Answer 49

Strong Quick Discontinuous Voluntary

Question 50

What are the four properties of cardiac muscle tissue?

Answer 50

Strong Quick Continuous Involuntary

Question 51

What are the three properties of smooth muscle tissue?

Answer 51

Weak Slow Involutary

Question 52

What is the purpose/location of striated/skeletal muscle tissue?

Answer 52

Connected to skeleton for movement

Question 53

What is the purpose/location of cardiac muscle tissue?

Answer 53

Heart muscle

Question 54

What is the purpose/location of smooth muscle tissue?

Answer 54

Non skeletal muscle like diaphragm

Question 55

What 3 things make up connective tissue?

Answer 55

Elastin fibre Fibroblasts Collagen fibre

Question 56

What is the example of connective tissue?

Answer 56

Collagen (secondary fibrous protein)

Question 57

What do fibroblasts do?

Answer 57

Provide structured framework for many tissues | -most common cells of connective tissue in animals

Question 58

What are organs?

Answer 58

A group several tissues joining to carry out a particular function for the whole organism

Question 59

What is cytoplasm?

Answer 59

Gel-like substance that contains cell's organelles

Question 60

Whst is the structure found in all prokaryotes but not eukaryotes?

Answer 60

Mesosome- increases surface area

Question 61

What four structures are only found in bacterium?

Answer 61

Plasmid Pilus Flagellum Capsule

Question 62

What makes up viruses?

Answer 62

DNA or RNA enclosed in a protein coat (matrix). Contain no cytoplasm.

Question 63

What are the two DNA differences between eukaryotes and prokaryotes?

Answer 63

Prokaryotic has no organised nucleus with DNA free in cytoplasm and DNA circular whereas eukaryotic are bound by nuclear membrane and are linear strands (chromosomes)

Question 64

What are the two cell wall differences between eukaryotes and prokaryotes?

Answer 64

Prokaryotic has a protective slime capsule and is made of murein, eukaryotic has none and a cellulose cell wall

Question 65

What are the two internal and external size differences between eukaryotes and prokaryotes?

Answer 65

Prokaryotic have smaller ribosomes (70s) and smaller over all size (10um) compared to 80s and 100um

Question 66

What is the site of respiration between eukaryotes and prokaryotes?

Answer 66

Prokaryotes' is foldings of cell membrane called mesosomes whereas eukaryotic's is mitochondria

Question 67

What does prokaryotic not contain?

Answer 67

Membrane bound organelles