B1.1

Question 1

What is the difference between prokaryotic and eukaryotic cells?

Answer 1

-Eu have nuclei which stores genetic material,pro have no nuclei, the genetic material floats in cytoplasm
-Eu are bigger
Prokaryotes are complex.

Question 2

What are the different main structures in an animal (eu) cell

Answer 2

Cytoplasm,nucleus,mitochondria,cell membrane

Question 3

What extra structures do plant cells have compared to animals?

Answer 3

Vacuole, cell wall, chloroplasts

Question 4

How many micrometers (um) in a meter?

Answer 4

1000000(1 x 10^6)

Question 5

What is one way you can observe bacteria growth?

Answer 5

On an agar plate

Question 6

Why dont potato cells have chloroplasts?

Answer 6

They grow underground
So they dont receive light
So they dont photosynthesise as light is needed for it
So they dont need chloroplasts as photosynthesis never happens

Question 7

How do you adjust the magnification and stage position in microscopy

Answer 7

Magnification - low to high
Stage - moving away from lens

Question 8

Whats the main structure that gives a bacterial cell(pro) its genetic info

Answer 8

A single long, somewhat circular strand of DNA called the (bacterial) chromosome

Question 9

Describe a plasmid

Answer 9

A circle of DNA, storing extra genes.They are helpful for times of stress, such as resistance genes

Question 10

What is a flagellum?

Answer 10

Tail like structures which help for movement through liquids

Question 11

What are pili?

Answer 11

Hair like structures that enable the cell to attach to substances, can also transfer genetic material

Question 12

What is a slime capsule?

Answer 12

A layer outside the cell wall preventing the bacteria from drying out,also helps in sticking to surfaces

Question 13

Why would you stain a cell?

Answer 13

Many cells are colourless or transparent,so stains are used to give them colour and make them easier to observe

Question 14

What stain for what specimen?

a - methylene blue
b - iodine
c - crystal violet

Answer 14

a - animal cells
b - plant cells
c - bacterial cells

Question 15

What is the smallest difference between 2 points seen as separate entities?

Answer 15

Resolution

Question 16

In light microscopy,why do specimen need to be thin

Answer 16

For images to be produced,a light shines through the specimen,so it needs to be thin

Question 17

Advantages and disadvantages of an electron microscope

Answer 17

Positive - high resolution, false colour can be added, high magnification
Negative - Expensive, large, needs training to prepare samples, cannot examine live specimen

Question 18

TEM vs SEM

Answer 18

Transmission/Scanning are both electron microscopes, but scanning produces in 3D instead of 2D. TEM sends electrons through the specimen, SEM sends them across the surface

Question 19

How do you apply a stain on a cell?

Answer 19

1. Place the cells on a glass slide
2. Add on drop of stain
3. Place a coverslip on top
4. Tap the coverslip gently with a pencil to remove air bubbles.

Question 20

What are the seven life processes every cell can carry out?

Answer 20

M - movement
R - reproduction
S - sensitivity
G - growth
R - respiration
E - excretion
N - nutrition