(Module 1) Cells and microscopes

Question 1

Microscope table

Answer 1

Image size
_____________
Actual Size X Magnification size

Question 2

A plant cell in a photograph measures 15mm across. If the actual size of the cell is 0.015mm, what is the magnification.

Answer 2

15 X 0.015 = 1000

Question 3

The nucleus of a cell in a photograph measures 3mm. If the magnification on the photograph is X 500, what is the actual size

Answer 3

3 / 500 = 0.006

Question 4

How strong is the light microscope

Answer 4

It has a magnification strength X 2000

Question 5

How strong is an electron microscope

Answer 5

It uses a beam of electrons to magnify X 2000000

Question 6

Factors of a prokaryotic cell

Answer 6

Single celled organisms - e.g bacteria
No nucleus
About 0.2 - 2 um
No membrane bound organelles (except ribosomes)

Question 7

Factors of a Eukaryotic cell

Answer 7

Multicellular organisms e.g animals, anything but bacteria
Have a nucleus
Approximately 10um - 100 um in length
Membrane bound organelles

Question 8

Parts of a Prokaryotic cell

Answer 8

Circular DNA
Cell wall
Ribosome
Plasma membrane
Slimy capsule
Cytoplasm
Flagellum (tail)

Question 9

What did Robert Hooke do

Answer 9

Discovered Plant cells

Question 10

What are the three types of cell movements

Answer 10

Diffusion
Osmosis
Active transport

Question 11

What is diffusion

Answer 11

Diffusion is the net random movement of particles from an area of high concentration to an area of low concentration e.g a deodorant being sprayed in a room.
Gas exchange at the alveoli of the lungs to the lungs.

Question 12

Factors that affect cell movement

Answer 12

Concentration gradient
Temperature
Surface area (of the membrane)

Question 13

What is osmosis

Answer 13

Osmosis is the net random movement of water molecules from an area of high water potential to an area of low water potential across a partially permeable membrane

Question 14

What is a dilute solution - what is a concentrated solution

Answer 14

More water, less solute

Less water, more solution

Question 15

Different types of solution

Answer 15

Hypertonic - high concentration of solute e.g lots of sugar
Hypotonic - lower concentration of solute e.g less sugar
Isotonic solution - equal concentrations of water and solute

Question 16

Different levels of plant cell water levels

Answer 16

Plasmolysed cell- this is where there is too little water- un fixable
Flaccid cell - equal solute concentrations inside and out the cell
Turgid cell - this is a plant cell with pure water outside.

Question 17

What is active transport

Answer 17

The movement of substances from an area of low concentration to higher concentration against the concentration gradient. E.G taking in vitamins through the small intestine

Question 18

Why is active transport different

Answer 18

Energy (from respiration in the mitochondria)

Question 19

Give an example of active transport in plants

Answer 19

Root hair cell

Question 20

Surface area to volume ratio

Answer 20

Cells are more efficient at exchanging substances when they have a large surface area to volume ratio - the smaller the cube, the bigger the ratio.

Question 21

Example of surface area to volume ratio

Answer 21

The alveoli