2.1 cell structure

Question 1

Name the 4 types of microscopes.

Answer 1

Optical microscope
Transmission electron microscope
Scanning electron microscope
Laser scanning confocal microscope

Question 2

What is an optical microscope?

Answer 2

It produces a 2D image and visible light passes through the specimen.

Question 3

What is a transmission electron microscope?

Answer 3

Electrons pass through a specimen to a detector. Produces a 2D image

Question 4

What is a scanning electron microscope?

Answer 4

Specimen is coated in metal, electrons scan across surface and electrons bounce off to detectors. Produces a 3D image.

Question 5

What is a laser scanning confocal microscope?

Answer 5

Laser scans across specimen but scans at different depths to view different layers. Produces a 3D image of interior.

Question 6

Pros of optical microscopes.

Answer 6

Can view living organisms.

Question 7

Cons of optical microscopes.

Answer 7

Lower resolution and magnification than electron microscope.

Question 8

Pros of electron microscopes.

Answer 8

Higher resolution and magnification

Scanning electron microscope produces 3D images.

Question 9

Cons of electron microscopes.

Answer 9

Thin specimen required
Can only view dead specimens
Complicated processing which can result in artefacts.

Question 10

Pros of laser scanning confocal microscopes.

Answer 10

Can view living organisms
3D images
Higher resolution than optical microscope

Question 11

Cons of laser scanning confocal microscopes.

Answer 11

Lower resolution than electron microscopes.

Question 12

What does resolution mean?

Answer 12

Smallest distance apart where 2 objects are seen as separate.

Question 13

How can you increase contrast?

Answer 13

By adding a stain. (differential stain)

Question 14

What is the magnification equation?

Answer 14

Image size = actual size x magnification

Question 15

What is a graticule?

Answer 15

A ruler which is fitted into the eyepiece of a microscope.

Question 16

Why do we use graticules?

Answer 16

Used to measure specimens.

Question 17

What is a stage micrometer?

Answer 17

Microscopic ruler on a microscope slide.

Question 18

What does the nucleoplasm do?

Answer 18

Chemical reactions take place.

Question 19

What does the nuclear membrane do?

Answer 19

Breaks up the DNA from cytoplasm.

Question 20

What does the nucleolus do?

Answer 20

It is a dense region of RNA

Question 21

What do nuclear pores do?

Answer 21

Allow transport between nucleus and cytoplasm.

Question 22

What does the matrix in mitochondria do?

Answer 22

A liquid where chemical reactions take place.

Question 23

What do 70S proteins do?

Answer 23

Site of protein synthesis.

Question 24

What does circular DNA do?

Answer 24

Contains genetic info.

Question 25

What does the outer and inner mitochondrial membrane do?

Answer 25

Create a partially permeable membrane.

Question 26

What do ribosomes do in the RER?

Answer 26

Copy of a gene passes through them and it reads the code to make the protein.

Question 27

Why do RER have a large surface area?

Answer 27

For protein synthesis.

Question 28

Why happens in the golgi apparatus?

Answer 28

Protein from the RER passes through layers of the golgi and the protein pinches off and is enclosed in a vesicle.

Question 29

What is the role of the smooth endoplasmic reticulum?

Answer 29

Produces lipids and carbohydrates?

Question 30

What is a vesicle?

Answer 30

An organelle which transports substances around, into or out of cells.

Question 31

What is a lysosome?

Answer 31

Vesicle containing digestive enzymes.

Question 32

Name the 7 features of chloroplasts.

Answer 32

``` Inner membrane Outer membrane Stroma Granum Thylakoids Integranal lamellae Inter membrane compartment ```

Question 33

Chloroplasts are the site of what?

Answer 33

Photosynthesis

Question 34

Role of the vacuole?

Answer 34

Support the plant | It’s surrounded by a membrane called the tonoplast.

Question 35

Function and features of ribosomes.

Answer 35

Made of ribosomal RNA Made in nucleolus Protein synthesis.

Question 36

Role of centrioles?

Answer 36

Contain microtubules which are made of tubulin protein. Before the cell divides the spindle, made of threads of tubulin, forms the centrioles. Centrioles form cillia & undulipodia.

Question 37

Role of cilia and undulipodia?

Answer 37

Contain microtubules Formed by centrioles Cilia: move materials along surface of cell Undulipodia: moves cell itself

Question 38

Role of cytoskeleton?

Answer 38

Protein microfilaments give support and mechanical strength.

Question 39

Role of cellulose cell wall

Answer 39

Strength, support, shape

Question 40

Role of flagellum?

Answer 40

Allow bacteria to move.

Question 41

Role of pili?

Answer 41

Small, hair like structures that allow bacteria to adhere to each other or to host cells.

Question 42

What is the nucleoid?

Answer 42

Circular DNA

Question 43

What is a plasmid?

Answer 43

A DNA loop.

Question 44

Name the 8 structures oh prokaryotes?

Answer 44

``` Capsule Ribosome Flagellum Pili Plasma membrane Nucleoid Plasmid Peptidoglycan cell wall ```