Senior Science

Question 1

List a few chemicals used in everyday life (3)

Answer 1

Cleaner - emulsifies
Lubricants - reduces friction
Cosmetics - slows water loss

Question 2

What is the tyndall effect?

Answer 2

Light that is visible passing through a…colloid/suspension

Question 3

List mixtures according to particle size:

Answer 3

Small - solutions
Medium - colloids
Large - suspensions

Question 4

Provide an example of each mixture (solution, colloid, suspension)

Answer 4

Solution - soft drink
Colloid - milk
Suspension - flour suspended in water

Question 5

What is a solution?

Answer 5

Dissolved particles, uniformly distributed

Question 6

What is a colloid?

Answer 6

Particles that are suspended, do not filter but settle

Question 7

What is a suspension?

Answer 7

Particles that separate over time, can be filtered

Question 8

List 4 types of colloids

Answer 8

Emulsions
Foam
Sol/gel
Aerosol

Question 9

What is an emulsifier?

Answer 9

Substance that allows dispersion of liquids

Question 10

Define surface tension

Answer 10

Forces between molecules in a liquid, pulling them inward

Question 11

Define miniscus

Answer 11

Shape that the surface of a liquid takes in a tube

Question 12

How does a surfactant work?

Answer 12

Where a molecule dissolves into an oil substance, REDUCING SURFACE TENSION

Question 13

Define the purpose of an emulsion

Answer 13

Dispersion of droplets of one liquid into another which are not soluble

Question 14

Define biodegradable

Answer 14

Substance that can be broken down by living organisms

Question 15

Why is skin classified as an organ?

Answer 15

Because it contains a minimum of two tissues working together

Question 16

Where are new cells made?

Answer 16

Low layerm of epidermis

Question 17

Functions of the skin?

Answer 17

• Heat regulation
• Protection
• Excretion
• Sensation
• Immune response

Question 18

What is the purpose of micro-flora on the skin?

Answer 18

Mutualism occurs as micro-flora break down sebum into fatty acids to maintain the slight acidity of the skin

Question 19

What are the 2 most commonly used solvents and why?

Answer 19

Water - due to polarity of water allows greater attraction and dissolving
Ethanol: It contains carbon atoms and is ‘organic’

Question 20

For a drug to be effective it must…

Answer 20

• Reach target at correct doasage
• treat
• last long to take effect
• only affect tissues designed for
• have few side effects

Question 21

What is the pH of the skin, mouth, stomach and small intestine?

Answer 21

Skin: 5.5
Mouth: 8
Stomach: 3
Small Intestine: 9

Question 22

What are two types of tablets?

Answer 22

Enteric-coated

Slow-release eg. Osmotic pump

Question 23

What is the purpose of an enteric-coated tablet?

Answer 23

Remains intact within the stomach, released in small intestine to be absorbed into bloodstream

Question 24

Define vitamins

Answer 24

Organic molucules needed for: growth, reproduction, maintenance, that speed up reactions of enzymes. Either FAT or WATER soluble

Question 25

Difference between FAT/WATER soluble vitamins?

Answer 25

Fat - persist within the body | Water - readily excreted

Question 26

List 2 biomedical devices and their use/material

Answer 26

Pacemakers: Control beating of heart - silicone plastic | Plates/pins/screws: Hold bones together - metal

Question 27

What are the tricuspid valves?

Answer 27

Valves that prevent back-flow of blood

Question 28

What is diastole and systole?

Answer 28

Diastole: Ventricles relax Systole: Ventricles contract

Question 29

What are the 5 sections of an ECG?

Answer 29

PQRST

Question 30

List 2 types of replaceable valves

Answer 30

Bi-leaflet 1970's - blood clotting | Allograft 1960's - dead people

Question 31

Negative consequences of atherosclerosis

Answer 31

Obstruction of blood flow Can cause blood clots Weakens walls of arteries

Question 32

List 2 materials used in boimaterials

Answer 32

Plastic (UHMWPE, silicone) | Metals (Super alloys)

Question 33

What are 4 types of movable joints?

Answer 33

Hinge Ball-n-socket Gliding Pivot

Question 34

What is a heart-lung machine?

Answer 34

Maintains functions of heart/lungs while either or both cannot work

Question 35

Compare minimally/non-invasive

Answer 35

Minimally: Cheap, longer recovery Non: Cheap, painless, less effective

Question 36

List 2 types of minimally invasive techniques

Answer 36

x-rays- x-rays sent through body produce image of bones | Keyhole- Instruments fed through vessels to carry out surgery of tissues/organs

Question 37

Process of info transfer

Answer 37

Code -> message -> transmission -> decoder

Question 38

Define diode

Answer 38

Type of decoder

Question 39

3 classification systems of telecommunications

Answer 39

verbal? electronic? distance..?

Question 40

List the 4 main types of EMS waves giving an example for each

Answer 40

Visible light - optical fibres Infra-red - thermal imaging Microwaves - satellites for mobile networks Radio waves - TV, radio

Question 41

Advantages of using EMS as a form of communication

Answer 41

Light speed Travels in a straight line Reflected - signals can be deliberately bounced off the ionosphere

Question 42

Define geostationary satellites

Answer 42

"same time as Earth" travels at speeds in the same position relative to Earth - to ensure same position from Earths satellite dishes

Question 43

Define scanners

Answer 43

Narrow beam of light scans, scanning into a series of thin lines

Question 44

Define total internal reflection

Answer 44

When incident angle in a slow medium is greater than critical angle

Question 45

Advantages of optical fibres

Answer 45

multiplex, large bandwidth, secure, no interference

Question 46

CNS?

Answer 46

Brain Spinal cord Nerves

Question 47

3 types of neurones (sim)

Answer 47

sensory interneuron motor

Question 48

Sensory neuron

Answer 48

From body

Question 49

Interneuron

Answer 49

Messages between sensory/motor

Question 50

Motor neuron

Answer 50

From CNS to muscles/glands

Question 51

Sense organs?

Answer 51

Detect stimuli from inside/outside body. They detect specific stimuli

Question 52

Effectors? Examples

Answer 52

Organs that act to motor neuron signals (glands/effectors)

Question 53

Reflex arc?

Answer 53

Receptors receive stimuli that requires immediate response to prevent harm

Question 54

What 4 things does the circulatory system transport?

Answer 54

Nutrients, waste, oxygen, hormones

Question 55

3 types of blood vessels?

Answer 55

Arteries, capillaries, veins