1. Cell Structure

Question 1

Two types of cells

Answer 1

Prokaryotic and eukaryotic

Question 2

Prokaryotic cells

Answer 2

Single celled organisms (bacteria)

Question 3

Eukaryotic cells

Answer 3

Multicellular organisms (plants and animals)

Question 4

Plasma membrane

Answer 4

Found on the surface of animal cells plant cells and prokaryotic cells

Made from lipids and protein

Function: regulates the movement of substances in and out of the cell

Question 5

Cell wall

Answer 5

Found in plant cells

Rigid structure made from cellulose

Function: support

Question 6

Nucleus

Answer 6

Surrounded by a nuclear envelope, which is a double membrane, containing many pores. Nucleolus inside nucleus. Contains chromatin.

 function: controls the cells activities (transcription), DNA contains instructions to make proteins and the pores allows substances to move between nucleus and cytoplasm.


Question 7

Nucleolus

Answer 7

Found in the nucleus

Function: make ribosomes

Question 8

Lysosome

Answer 8

Contains digestive enzymes

Function: can be used to digest invading cells

Question 9

Ribosome

Answer 9

Made from proteins and RNA

Function: site where proteins are made

Question 10

Rough endoplasmic reticulum

Answer 10

System of membrane is covered with ribosomes

Function: fold and process proteins that have been made by ribosomes

Question 11

Smooth endoplasmic reticulum

Answer 11

System of membranes without ribosomes

Function: synthesise and process lipids

Question 12

Vesicle

Answer 12

Can be formed by the Golgi and ER or the cell surface

Function: transport substances in and out of the cell and between organelles

Question 13

Golgi apparatus

Answer 13

Function: process and package new lipids and proteins and make lysosomes

Question 14

Mitochondrion

Answer 14

Double membrane in a membrane is folded to form cristae. Inside is the matrix which contains enzymes involved in respiration. Require a lot of energy

Function: site of aerobic respiration where ATP is produced

Question 15

Chloroplast

Answer 15

Double membrane has internal membranes (thylakoid membranes). These are stacked up in some parts to form grana. Grana and thylakoid membrane is linked together by lamellae.
Contains chlorophyll which absorbs light for photosynthesis

Function: site of photosynthesis. Some parts of photosynthesis happen in the grana and other parts in the stroma

Question 16

Centriole

Answer 16

Made from microtubules, found in animal cells and some plant cells

Function: separation of chromosomes

Question 17

Cilia

Answer 17

Hair-like structures

Function: movement of substances along the cell surface

Question 18

Flagellum

Answer 18

9+2 formation

Function: movement

Question 19

Protein production

Answer 19

Proteins are made at ribosomes
Ribosomes on the rough endoplasmic reticulum make proteins that are attached to the cell membrane. The ribosomes in the cytoplasm make proteins that stay in the cytoplasm
Proteins produced at the RER are folded and processed then transported to the Golgi apparatus and vesicles. Processed further
Proteins go into more vesicles to be transported around the cell

Question 20

Cytoskeleton

Answer 20

Network of protein threads arranged as microfilaments and microtubules
Functions: support organelles keeping them in position, strengthen the cell, movement of materials within the cell, allow the cell to move.

Question 21

Prokaryotic DNA vs eukaryotic DNA

Answer 21

Circular vs linear

Question 22

Size of prokaryotes

Answer 22

Less than two micrometres diameter

Question 23

Size of eukaryotes

Answer 23

10 to 100 micrometres diameter

Question 24

What is the cell wall made out of in prokaryotes?

Answer 24

Polysaccharide

Question 25

What is the cell wall made out of in eukaryotes?

Answer 25

Cellulose or chitin

Question 26

Light microscopes

Answer 26

Use light
Small resolution (0.2 micro metres)
Maximum magnification x1500

Question 27

Laser scanning confocal microscope

Answer 27

Use laser beams with fluorescent dye
Attached to a computer to generate an image can be 3D.
Can be used to look at different depths. 

Question 28

2 types of electron microscopes.

Answer 28

Transmission and scanning.

Question 29

Transmission electron microscope.

Answer 29

Use electromagnets to focus a beam of electrons.
Denser parts absorb more electrons.
High resolution (0.0002 micrometers).
Magnification - x1,000,000 and can be more.
Can only be used on thin specimens.

Question 30

Scanning electron microscope.

Answer 30

Beam of electrons across specimen.
Shows the surface of the specimen and can be 3D.
Lower resolution than TEM (0.002 micrometres)
Magnification - less than 500,000

Question 31

Staining for light microscopes.

Answer 31

Using dye.
Different dyes make different things show up.

Question 32

Specific dyes and their uses.

Answer 32

Eosin - cytoplasm.
Methylene blue - DNA.

Question 33

Staining for electron microscopes.

Answer 33

Dipped in solutions of heavy metals (lead).

Question 34

Preparing a microscope slide.

Answer 34

Take a thin slice.
Use tweezers to put it into the middle of the slide.
Use a cover slip.

You can also wet mount using a drop of water.

Question 35

Using a light microscope.

Answer 35

Put the slide on the stage.
Select the lowest powered objective lens.
Use the coarse adjustment knob to move the stage.
Look down the eyepiece lens and use the coarse adjustment knob to focus the image.
Use the fine adjustment knob to get a clear image.
Move to a higher powered objective lens.

Question 36

Eyepiece graticule.

Answer 36

Fitted to the eyepiece.
Has numbers but no units.

Question 37

Stage micrometer.

Answer 37

Microscope slide placed on the stage.
Accurate scale with units.
Used to calculate the value of the divisions in the eyepiece graticule at a particular magnification.
Measure the size of the specimen.

Question 38

Stroma.

Answer 38

Contains enzymes to aid photosynthesis
Contain starch grains for an energy store