B1.1

Question 1

Eukaryotic cells

Answer 1

Cells that contain genetic material in a nucleus

Question 2

Prokaryotic cells

Answer 2

Cells that do not contain a nucleus.
Their genetic material floats in the cytoplasm.
Smaller than eukaryotic

Question 3

Name all the organelles eukaryotic cells contain

Answer 3

1. Nucleus
2. Cytoplasm
3. Mitochondria
   4.Cell membrane

Question 4

Name the 3 extra subcellular structures that plant cells have but not animal cells

Answer 4

1. Chloroplast
2. Cell wall
3. Vacuole

Question 5

Function of the nucleus

Answer 5

Contains genetic material
Controls activities of cell
Determines cell appearance

Question 6

Function of cytoplasm

Answer 6

Jelly like substance where chemical reactions take place

Question 7

Function of mitochondria

Answer 7

Power house of cell. Where respiration takes place

Question 8

Function of cell membrane

Answer 8

Controls what goes in and out of the cell

Question 9

Functions of chloroplast

Answer 9

Where photosynthesis takes place

Question 10

Function of cell wall

Answer 10

Provides support for the cell

Question 11

Function of vacuole

Answer 11

Contains cell sap and helps keep cell firm

Question 12

Mrs Nerg?

Answer 12

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

Question 13

What subcellular structures to prokaryotic cells contain

Answer 13

1. Cytoplasm
2. Genetic material
3. Cell membrane
4. Cell wall

Question 14

Name extra subcellular structures if prokaryotic cells

Answer 14

1. Flagella
2. Pilli
3. Slime capsule
4. Plasmid

Question 15

Function of flagella

Answer 15

Tail like structures that allow the cell to move through liquids

Question 16

Function of pilli

Answer 16

Tiny hair like structures that allow the cell to attach to structures

Question 17

Function of slime capsule

Answer 17

Protect bacterium from drying out from poisonous substances

Question 18

Function of Plasmid

Answer 18

Circular piece of DNA that is used to store extra genes .

Question 19

Function of ribosome (animal cell)

Answer 19

This is where proteins are made and is found in the cytoplasm

Question 20

3 examples of commonly found bacteria

Answer 20

• Escherichia coli (or E. coli), which cause food poisoning (Figure 2).
• Streptococcus bacteria, which cause sore throats (Figure 3).
• Streptomyces bacteria, which are found in the soil. The antibiotic streptomycin comes from these bacteria. It kills many disease-causing bacteria.

Question 21

Name the parts of a light microscope

Answer 21

1. Stage
2. Fine focus
3. Eyepiece lens
4. Objective lens
5. Slide
6. Light
7. Course focus

Question 22

How does a light microscope work

Answer 22

It passes light through an object places on the slide on the stage then through the 2 glass lenses which magnifies it.

Question 23

Formula for total magnification

Answer 23

Total magnification = eyepiece lens x objective lens

Question 24

How to use the light microscope

Answer 24

1. Move the stage to its lowest position.
2. Select the objective lens with the lowest magnification.
3. Place the slide, which has cells on it, on the stage.
4. Raise the stage to its highest position, taking care that the slide does not touch the lens.
5. Lower the stage slowly using the coarse focus knob until you see your
   object (it will normally be blurred).
6. Turn the fine focus knob slowly until your object comes into clear focus.

Question 25

Name 3 stains

Answer 25

1. Iodine 2. Methylene blue 3. Crystal violet

Question 26

What do the stains stain.

Answer 26

Methylene blue - animal cells nucleus Iodine - plant cell nuclei Crystal violet - bacteria cell walls

Question 27

What is resolution

Answer 27

A measure of the smallest object which can be seen using an instrument

Question 28

Name the 2 tropes of electron microscopes

Answer 28

1. Transmission electron microscopes (TEM) 2. Scanning electron microscopes (SEM)

Question 29

What are TEM microscopes.

Answer 29

TEM produce the most magnified images. They work in a similar way to a light microscope. A beam of electrons passes through a very thin slice of the sample. The beam is focused to produce an image

Question 30

what are SEM microscope

Answer 30

produce a three-dimensional image of a surface. They send a beam of electrons across the surface of a specimen. The reflected electrons are collected to produce an image.

Question 31

What are electron microscopes

Answer 31

Electron microscopes use electrons instead of light to produce an image.

Question 32

Compare light and electron microscopes

Answer 32

Light microscope • Cheap to buy and operate • Small and portable • Simple to prepare a sample • Natural colour of sample is seen unless staining is used • Specimens can be living or dead • Resolution up to 0.2 um (2 × 10-7 m) Electron microscope: • Expensive to buy and operate • Large and difficult to move • Sample preparation is complex • Black and white images produced; false colour can be added to image • Specimens are dead • Resolution up to 0.1 nm (1 x 10-10 m)