Bio 3- Cell structure

Question 1

Whats the equation for magnification?

Answer 1

magnification = image size / actual size

Question 2

Explain the process of centrifuge.

Answer 2

• tissue is cut up and kept in a cold buffered solution
• tissue further broken up in a homogeniser
• Homogenised tissue is spun in an ultracentrifuge at low speed
• Heaviest thing goes to the top and is removed
• Tissue spun again at higher speeds until desired cell is seperated

Question 3

How does a TEM work?

Answer 3

• Produces beam of electrons that is focused onto the specimen.
• A beam passes through a thin section of the specimen
• Image produced on a screen

Question 4

Can living things be used in a TEM, give a reason.

Answer 4

Whole system uses a vacuum so living things can’t be observed

Question 5

How does SEM work?

Answer 5

Directs a beam of electrons on the surface of the specimen.

Question 6

List three differences between SEM and TEM.

Answer 6

• SEM has lower resolving power than TEM
• SEM is 10x more powerful than a TEM
• Specimen in SEM don’t have to be thin like in a TEM

Question 7

What happens in the mitochondria?

Answer 7

Its the site for aerobic respiration

Question 8

What organelle carries out photosynthesis?

Answer 8

Chloroplast

Question 9

What is the endoplasmic reticulum?

Answer 9

3D system of sheet-like membranes in the cytoplasm.

Question 10

What are the two types of endoplasmic reticulum?

Answer 10

• rough endoplasmic reticulum

- smooth endoplasmic reticulum

Question 11

What’s the function of the endoplasmic reticlum?

Answer 11

To transport synthesized proteins to the Golgi apparatus

Question 12

What are Golgi apparatus made up of?

Answer 12

A stack of membranes which form flattened seas called cisternae, which contain hollow structures called vesicles

Question 13

What do cisternae contain?

Answer 13

Hollow structures called vesicles.

Question 14

Is the Golgi apparatus found in eukaryotic or prokaryotic cells?

Answer 14

Eukaryotic cells

Question 15

Whats the function of the Golgi apparatus

Answer 15

Produces secretary vesicles

Question 16

When are lysosomes found.

Answer 16

When the Golgi apparatus vesicles contain protease + lipids.

Question 17

What are lysozymes.

Answer 17

enzymes that hydrolyse the cell wall.

Question 18

What’s the function of lysosomes.

Answer 18

Contains hydrolytic enzymes

Question 19

Where are ribosomes found?

Answer 19

The cytoplasm

Question 20

What are the two types of ribosomes?

Answer 20

8Os - found in eukaryotic cells

7Os - found in prokaryotic cells

Question 21

Where is the site of protein synthesis?

Answer 21

Ribosomes

Question 22

What makes the cell wall strong?

Answer 22

Microfibrils

Question 23

Name 2 features of the cell wall.

Answer 23

• lots of polysaccarides

- thin layer called middt lamella that makes a boundary

Question 24

What is cell differentiation?

Answer 24

The process by which a cell becomes specialised in order to perform a specific function.

Question 25

Nucelar envelope : eukaryotic or prokaryotic?

Answer 25

Eukaryotic

Question 26

Cell wall : eukaryotic or prokaryotic?

Answer 26

Prokaryotic

Question 27

Ribosomes : eukaryotic or prokaryotic?

Answer 27

Prokaryotic and Eukaryotic

Question 28

Plasmid: eukaryotic or prokaryotic?

Answer 28

Prokaryotic and Eukaryotic

Question 29

Cell-surface membrane : eukaryotic or prokaryotic?

Answer 29

Prokaryotic and Eukaryotic

Question 30

Mitochondria: eukaryotic or prokaryotic?

Answer 30

Eukaryotic

Question 31

How do bacterial cells protect themselves?

Answer 31

by secreting a capsule of mucilaginous slime around wall.

Question 32

How do bacterial cells store food?

Answer 32

They store food reserves as glycogen granules and oil droplets

Question 33

Does a virus contain DNA or RNA?

Answer 33

It contains both

Question 34

When can a virus multiply?

Answer 34

Inside living host cells.

Question 35

What are viruses surrounded by?

Answer 35

A lipid envelope

Question 36

What is attached to lipid proteins/ capsid?

Answer 36

Attachment proteins

Question 37

What do attachment proteins do?

Answer 37

Allow the virus to identify and attach to a host cell.

Question 38

What is Mitosis?

Answer 38

Division of a cell that results in each of the daughter cells having an exact copy of the DNA of each parent cell.

Question 39

What phase does DNA replication happen in?

Answer 39

Interphase

Question 40

What happens in prophase?

Answer 40

- Chromosomes first become visible | - Spindle fibres develop

Question 41

What happens in metaphase?

Answer 41

- Spindle fibres arrange themselves across the equator of the cell

Question 42

What happens in anaphase?

Answer 42

- the spindle fibres pull the individual chromatids apart and pulled to opposite polls of the cell

Question 43

What happens in telophase?

Answer 43

- chromatids reached their respective poles | - nuclear envelope and nucleolus re-form.

Question 44

In the cell cycle, does division happen in interphase?

Answer 44

No

Question 45

What is cancer?

Answer 45

The result of damage to the genes that regulate mitosis which leads to uncontrolled growth + cell division

Question 46

What two things effect the rate of mitosis?

Answer 46

- the cells environment | - growth factors

Question 47

How are cancer cells killed?

Answer 47

A part of the cell cycle is blocked and disrupted therefore cancer growth stops

Question 48

How do they disrupt the cell cycle?

Answer 48

- preventing DNA replication | - inhibiting metaphase stage, interfering with spindle fibre formation